SIGMA - Thomson T-Line Caravans History and · PDF file · 2015-11-04ing procedure will assist in the application ... or scissor type jack. ... and damper assembly; and under the

SIGMASERVICE AND MAINTENANCE INSTRUCTIONS

FOR B & B CHASSIS

FITTED WITH

SIGMA BACK-UP BRAKING SYSTEM

AND B & B SUSPENSION EQUIPMENT

Covering the period 1972 until 1983

AL-KO Kober Ltd, South Warwickshire Business Park, Kineton Road, Southam, Warwickshire, CV47 0AL. Tel: 01926 818500

B & B - Chassis Service Information

Coupling Up (Kappa)

Having actioned the thumb operated latchinto a rearward position, the handle maynow be lifted to its fullest extent where it willautomatically lock into position. Lower thecoupling onto the towing ball by using thejockey wheel. As the ball becomes en-gaged in the coupling, the handle will au-tomatically be released and therefore ef-fect a lock onto the ball. The safety catchwill now be engaged and it should not bepossible to fully raise the handle withoutfirst operating the thumb latch. The checkof the fully locked position should alwaysbe carried out before moving off.

Pass the breakaway chain round thetowball on the car and connect it back ontothe chain by the snap hook. Ensure plentyof slack.

Fully wind up the telescopic jockey wheel.Release the jockey wheel clamp and liftthe jockey wheel stem to the highest posi-tion.

(This paragraph also relates to theAutolock)

Uncoupling (Kappa)

Remove the breakaway cable and discon-nect the 7-pin plugs. Release the jockeywheel clamp and lower jockey wheel toground. Having actioned the thumb oper-ated latch into a rearward position, lift thehandle to it's fullest extent and wind downthe jockey wheel which will lift the couplingclear of the ball, as the ball is released thehandle will lock into the raised position. Torelease the handle from this position pushthe thumb latch in a forward motion, thiswill enable the handle to be lowered to itsoriginal position.

AutolockHead

KappaHead

Coupling Head(Autolock or Kappa)

The coupling head is entirely automatic inoperation and has been designed to suitthe 50mm International Sandard Ball rec-ommended by the British Standards Insti-tute, The National Caravan Council andthe Society of Motor Manufacturers andTraders.

Coupling Up (Autolock)

Having depressed the safety catch on theside of the socket head, press the couplingdown on to the ball. This action will lift themain locking plunger which, when the headis firmly on the ball, will return to the fullydown position. The spring loaded safetycatch on the side of the coupling head alsoindicates whether the main plunger is rightdown to the fully locked position. If the clipdoes not automatically engage under thelug it means that foreign matter has foundits way into the ball housing.

It is imperative that the coupling headlocking handle is in the fully down posi-tion before commencing to tow.

Uncoupling (Autolock)

Having pressed the safety catch, lift thehandle on the coupling head and "roll" thesocket head so that the bottom of thecoupling head makes contact with the stemof the ball and acts as a simple lever. If atelescopic jockey is fitted, having pulledthe coupling handle up, wind the jockeywheel down. This action will lift the sockethead clear of the ball.

Reversing

The B&B SIGMA "Back-Up" braking sys-tem eliminates the need for a lock outdevice or clip when reversing. If the brakesare found to be locking up when reversing,then they are over-adjusted or the collapsemechanism inside the brake is not func-tioning.

Parking -Handbrake Application

The SIGMA "Back-Up" system is designedto permit easy reversing of the caravanwithout any special action on the part of thedriver to negate the operation of the brak-ing system. The system, however, requiresthat, when parking, the handbrake is cor-rectly applied, particularly when parkingon a reverse slope. Under most normalconditions the handbrake should be ap-plied with a hand load of not less than 40kgf. If parked on a reverse slope the follow-ing procedure will assist in the applicationof the handbrake and ensure that the cara-van is safely parked. Apply the hand brakewith a force which will just allow the cara-van to roll in a controlled manner. As thecaravan rolls, a "click" from each brakemay be heard, confirming that the shoeshave moved into the reverse position, fur-ther apply the handbrake until the caravanis firmly held, by the handbrake, againstthe effect of the gradient. Check security ofthe caravan before leaving. (It should benoted that it is good common practice tochock the wheels of the caravan whenparking on steep slopes, or under adverseconditions, such as loose or slippery sur-faces).

Jacking

Under no circumstances must the cornersteadies be used to jack up the unit. If it isnecessary to jack up, use a bottle, screw,or scissor type jack. Place the head underthe suspension arm as near to the springas possible if the chassis is fitted with a coiland damper assembly; and under the axletube as near as possible to the main longi-tudinal member if the chassis is fitted witha torsion bar assembly.

Page 2

Recommended tyre pressures:

Cross Ply: 4 ply rating 30psi6 ply rating 36psi

Radial: 155 SR - 13 35 psi (2.4Bar)155 SR - 13 Reinforced 42 psi (2.9 Bar)175 SR - 13 36 psi (2.5 Bar)175 R - 13C 6 ply 54 psi (3.75 Bar)185 SR - 13 36 psi (2.5 Bar)185 SR - 13 Reinforced 45 psi (3.1 Bar)

Note: It is customary for tyre manufacturers to mark the tyres with load andinflation data. It is important to understand that this information relatesonly to the use of the tyre on cars.

Page 3

Maintenance

1 Adjustment to Brakes

It is essential in making adjustments to the braking system toadjust firstly the brakes themselvesand secondly the coupling.

(a) Jack up axle raising wheelclear of ground.

(b) Remove wheel trim if necessary re-move road wheel. The road wheelhas a hole between two of the studholes which, when aligned with thehole in the brake drum, allows accessto the adjuster without removing thewheel. If necessary, re-position wheelto suit, ensuring that wheel nuts aretight 65 lbs/ft. - in sequence - i.e.North,South, East, West.

(c) Ensure that the drawshaft is ex-tended and that there is free play inthe brake rod.

(d) IMPORTANT:

During brake/hub adjustment, thedrum must only be revolved in aforward direction.

(e) Revolve brake drum until adjustmenthole is in line with slot-headed adjust-ment screw, then with a screwdriverrotate the adjustment screw in a clock-wise direction as far as it will go andreturn it two clicks ensuring at thesametime that the brake drum re-volves freely. This brake is then cor-rectly adjusted.

(f) After adjusting at wheel, apply hand-brake once or twice and re-checkadjustment.

g) Carry out similar procedure on op-posite wheel.

2 Adjustment to Sigma Coupling

Having adjusted the brakes (sec-tion 1), ensure that the drawshaftis fully extended i.e. normal tow-ing position. Check that the brakerods are straight and have no kinksor bends and the compensatorson the axles are free.Adjust the nuts on the front end ofthe brake operating rod to giveclearance of 5-10mm between thehandbrake and the overrun leverwhen the lever is held back to takeup all the free movement in thebrake linkage.

Check the clearance between theoverrun lever and the drawshaft. Ifthis is less than 13mm, increase itto 13mm.

Extreme care must be taken not toover-adjust the brake rod, other-wise the back-up action of thebrakes will be affected.

Check that the brakes are func-tioning correctly. Apply handbrakefully and then push caravan in re-verse. As the caravan rolls, a "click"from each brake may be heardand then the brake should hold thecaravan from further movement.If, however, the brakes do not holdthe caravan in reverse, then fur-ther adjustment is required of thebrake rod at the coupling until itwill hold the caravan in reverse.Check now that there is not brakedrag in the forward direction.

3 Tyre Maintenance

In order to equalise tyre wear, it issuggested that the wheels be bal-anced and changed round fromtime to time. Always use a socketand wrench when tightening wheelnuts to our recommended torqueof 65lbs/ft.

4 Steel Torsion Bar SuspensionSystem (Early 1980's)

The suspension system of the solidround steel torsion bar type hasbeen designed and developed tosuit all types of road conditionsand for easy maintenance lubrica-tion points are installed on theaxles. These consist of greasenipples sited at each end of themain suspension tube. Servicingat this point should take place atleast once every year with a lib-eral amount of grease to ensurethat both inner and outer bearingin the main tube receive lubricant.The hydraulic dampers are of thesealed non-adjustable type andrequire no service, damper alsoincorporates bump and reboundstops, therefore never tow thecaravan with the dampers re-moved. The torsion springs anddampers have been selected tosuit the unladen weight of the cara-van plus an additional amount forpersonal effects.


Adjustment: Independent Suspension System

A

Main Member

Swinging Arm

CB

Swinging Arm shows MKII (2) assembly (See page 12)

MKIII (3) Suspension adjustment as MKIIMKIII (3) Swinging Arm will be set inside Main Member.

The coupling plunger housing ispacked with grease on the assem-bly, but will require periodic oiling.

The Kappa coupling head mecha-nism is lubricated on assembly. Theonly service lubrication necessaryis to occasionally oil the pivot pinssparingly.

The brake lever fulcrum and springloaded ratchet should be oiled regu-larly. Grease should also be ap-plied to the surface of the hand-brake that is in contact with theoverrun lever.

Lubrication - Telescopic JockeyWheel

The operating mechanism ispacked with grease on assembly.Subsequent oiling is to be madethrough the small hole in the oper-ating handle. The wheel itself shouldbe oiled from time to time, also theclamp handle threads.

Lubrication - Corner Legs

The screw, nut and linkage pointsshould be lubricated from time totime.

Lubrication - Brake Linkage

All moving parts should be lubri-cated periodically to ensure satis-factory operation.

NOTE: When lubricating withgrease "Mobilgrease MP" or itsequivalent should be used.

For further information contactRichard Miller-Mead at AL-KOKober Ltd.

Telephone: (0926) 452828

Service Information 02/90

6 Lubrication - Brake Drum/HubAssembly

The brake hubs are packed withgrease to the correct level beforeleaving our works and should berepacked at approximately 3000mile intervals. To remove the"press-in" grease retaining cap, taplightly round the periphery. Note: Itis as important not to over pack thehubs with grease as it is to allowthe bearings to run dry.

When refitting the hub nuts shouldbe tightened to 65 lbs/ft. and thenslackened off 1 to 1 1/2 flats and anew split pin inserted. Finally checkthat the hubs rotate freely.

Lubrication - Sigma HydraulicCoupling

It is important that regular attentionis given to the two grease nipplesserving the coupling shaft bear-ings and the grease nipple on theoverrun lever.

Page 4

5 Independent SuspensionSystem

The suspension system is of thecoil and hydraulic damper type alsodesigned and developed to suit alltypes of road conditions, and foreasy maintenance only the hubsand brakes will require further at-tention. The swinging arm assem-bly is mounted in nylon busheswhich will not require further lubri-cation. The hydraulic dampers areof the sealed non-adjustable typeand will not require attention.Thesprings and dampers have beenselected to suit the unladen weightof the caravan, plus an additionalamount for personal effects.

The independent suspension canbe adjusted whether to level thecaravan or compensate for load.The correct position of the swing-ing arm is parallel to the main sus-pension member when thecaravan is laden for touring. Thesuspension can be adjusted as fol-lows: Undo locknut B and thenadjust by rotating bolt head A. (Note:Top plate C is threaded). Finallyretighten locknut. (As per diagram).

A

CB

BRAKE FAULT FINDING CHART

SYMPTOM POSSIBLE CAUSE REMEDY

Handbrake does not hold caravaneither forward or reverse.

1 Shoes incorrectly adjusted(carrier out of position).

2 Handbrake incorrectly adjusted.

3 Handbrake lever travel restricted.

1 Shoes incorrectly adjusted.

1 Brakes incorrectly adjusted.

2 Linings not bedded-in.

3 Incorrect lining material fitted.

4 Lining contaminated with grease.

5 Glazed brake lining surface.

6 Coupling shaft seized/bent.

1 Brakes incorrectly, adjusted onone side.

2 Lining contaminated with grease.

3 Brake rods bent.

4 Compensator pivots seized.

5 Odd linings side to side.

6 Brake drum cracked/distorted.

7 Brake backplate loose.

8 Odd tyres side to side/pressuresunequal.

9 Pull off spring/brake rod stopbroken/incorrectly set.

Handbrake holds in forward directionbut not in reverse.

Brakes on caravan ineffective/givelittle retardation.

Caravan brakinguneven/pulls to one side.

Adjust brakes to correct schedule.

Adjust at brake rod to correct schedule.

Ensure maximum number of notchesare obtainable.


Adjust brakes to correct schedule.Ensure all brake rod pivots are free.

Continue using brakes until linings arefully bedded. Re-adjust.

Check manufacturers spec. andreplace with correct type.

Rectify grease leak (fit new seal).Clean brake drum, fit new shoe/liningassemblies.

Clean off glaze with dampened smoothemery paper.

Examine, free off and regrease.Replace if bent.


Rectify as above.

Straighten rods.

Ensure all pivots are free,oil clevis pins, greasecompensators.

Check spec. and rectify.

Replace drum.

Check Fixings.

Fit similar tyres/check pressures.

Replace / reset(pull off spring tensioned to 6").

Page 5


BRAKE JUDDER

1. Ensure brake drums do not contain excessive dust.2. File off leading edge of leading brake shoe with a very gentle slope back 3/4 inch.3. If the above fails to cure the "judder", obtain from your dealer or

wholesaler a "107 SPRING KIT".

N.B. When this kit is fitted the handbrake must always be engaged fully.


Caravan brakes lock on whilstreversing.

1 Brakes over-adjusted.

2 Brakes adjusted with trailingshoes in reverse position.

1 Brakes incorrectly adjusted.

2 Faulty/damaged overrun damper.

3 Incorrect damper fitted.

4 Brake drums distorted/rusty.

5 Coupling shaft semi-seized/bent.

6 Towbar/bracket on towingvehicle flexible/loose.

7 Lining rivets loose/cracked lining.

Brake snatch causingshunting of caravan/brake judder.

Adjust brakes to correctschedule.

Adjust brakes to correct schedule(rotating wheel forwards).


Fit replacement damper.

Fit correct spec. damper.

Replace drum/clean up surface withemery paper.

(NB do not store caravan for longperiods with handbrake on).

Regrease. Replace if bent.

Ensure all fixings are tight. Checkflexibility by attaching vehicle tocaravan, applying caravan handbrakeand gently pulling away with anobserver checking any flexing.

Reinforce/replace towbar if necessary.


Page 6


1 Brakes over-adjusted.

2 Brake shoe pull of springsbroken/stretched/loose.

3 Brake shoe pull of springs fittedin wrong position or wrong typeused.

4 Brake rod pull of spring broken/stretched/loose.

5 Brake rod stop incorrectly set.

6 Expander assembly binding orseizing.

7 Wheel bearings over tight.

Brakes tend to bind/drag/lock/on/overheat.

(Note: Caravan brakes will rarely runcold. A warm hub/drum is normal).

Adjust brakes to correct procedure.

Examine all springs, replace if broken/loose. Particular attention should bepaid to spring adjacent to expanderbox.

Examine and rectify if necessary.

Replace/reset spring.

Release tension from pull off spring.Reset stop with brake fully off.Re-tension spring to 6"(152 mm).

Dismantle expander, lubricate spar-ingly and rebuild. Ensure expander isfree to slide in back plate slot.

Re-adjust hub nut.

WARNING

A proportion of the dust found in usedbrake and clutch parts/mechanism will be fine asbestos fibresand when removing friction dust from parts/mechanisms the following precautions should be

taken:-

1. Never use a brush or blow out with an air line.2. Always remove with a vacuum cleaner or wipe clean with a damp cloth.3. Place dust and used wet cloths in a plastic waste bag immediately after use.


Page 7


1

2

3

2

4

5

6

78

9

102

12 13

14

78

11

1615

2221

20

23

252627

2827

34

35

293031

3837

3834

39

40

4243

41

44

NOTE : Head and shaft assemblies will be supplied with an AL-KO head.

4648

47

Kappa Head

24

19 18

17

32

45

33

36

EEC SIGMA MK II HYDRAULIC OVERRUN ASSEMBLY CC3600

Page 8

EEC SIGMA MK II HYDRAULIC OVERRUN ASSEMBLY CC3600

* Check for availability

Page 9

PART PART No DESCRIPTION OF PART QTY

1 CC 3599 Overrun Lever 1*2 SP 553 Grease Nipple 33 CC 603 Iron Clip 24 CC 3601 Overrun Pivot Pin 12mm 15 CC 715 Pressure Pad 16 or ref 9 Rear Bolt, Fixing M.12 x 30 27 2505 SC Washer 48 Binx Nut M.12 49 Front Fixing Bolt M.12 x 120 410 CC 3506M Jockey Wheel Clamp Handle (Metric) 111 CC 3606 Body Casting 1*12 Full Nut M.10 213 Single Coil Washer M.10 SC 1*14 CC 2108 Handle 1*15 CC 1472A Spring 116 CC 1471A Plunger Nylon 117 CC 1470A Safety Catch Assembly 118 M.S. Pin19 Safety Catch Bolt M.10 x 5020 CC 1653 Inner Spring 121 CC 1266A Middle Spring 122 CC 1265A Outer Spring 123 CC 1261D Plunger 50mm 124 CC 1454 Mills Pin 125 CC 3613 50mm Head & Shaft Assembly 126 CC 3448 Bump Rubber 127 CC 3610 Split Ring 228 CC 3597 Damper Bracket 129 CC 3611 Retaining Washer 130 CC 3233 Tab Washer 131 Bolt M.6 x 12 132 CC 3706 Gaiter 133 04-22-070-103 Damper (Stabilus)34 Plain Washer M.13 235 Locking Bolt M.10 x 50 136 CC 4147 Damper Dirt Shroud (Stabilus) 137 CC 3491A Damper Rear Fixing Pin 138 CC 602 Iron Clip 339 CC 3898 Hand Brake Sub-Assembly 140 2008 Binx Lock Nut 5/16" UNF 141 CC 3633 Reach Nut 5/16" UNF 142 CC 3602 Brake Rod Swivel Pin 143 CC 604 Iron Clip 144 CC 3927 Hand Brake Plastic Grip 145 CC 3921 Hand Brake Release Button 146 CC 4899A Cover 147 CC 2760 Bellows 148 CC 6068 Hand Grip 1


1 2

3

4

5

25

2423

2221

15

14

132019

18

17

16

12

11109

8

67

2

SEE SEPARATEPARTS LIST

Page 14

ABOVE SHOWS RIGHT HAND SIDE ONLY

Page 10

TORSION BAR SUSPENSION 7", 8" OR 9" BRAKE

Page 11


1 CC 3801 M12 Socket Screw x 30mm 22 M12 L Locknut 23 CC 3787 Tube Housing N.L.A. 14 Torsion Bar

CC 3555 O/A Length 630mm (24.8") 2*CC 3554 O/A Length 578mm (22.75") 2*

5 CC 4669 Bush 26 CC 3254 Felt Washer 27 CC 3802 M12 Socket Screw x 45mm 2*8 CC 3719L or R Drop Arm Sub Assembly (Left or right Hand) 2*9 CC 3779 Damper Retaining Washer 2*10 1/2" Washer 211 CC 603 Soft Iron Clip 212 M12 110mm Bolt 213 CC 3778 Long Spacer 214 CC 3807 Short Spacer 215 CC 977A Spacing Washer 416 M12 Nut 217 HO 8008 Damper (Was CC 2644) 218 CC 1759 Pull Off Spring 219 CC 3429 Clevis Pin 220 SP 137 Split Pin 221 CC 3786 Brake Rod Sub Assembly 222 CC 602 Soft Iron Clip 423 CC 3795 Compensator Pivot Pin 224 CC 3529 Compensator N.L.A. 225 CC 4646 "O" Ring 2

*Check for availabilityN.L.A. - No Longer available

TORSION BAR SUSPENSION 7", 8" OR 9" BRAKE


141213

2

2

1

16

14

13

12

18

1715

19

96

85

20

10

4

11

7

Mark II (2)

Mark III (3)

INDEPENDENT SUSPENSION

3

Page 12

INDEPENDENT SUSPENSION

Page 13


1 CC2782 Brake Rod - 3/8" M.S. 1*Fork End

2 CC 2884 Rod/Fork Assembly 23 Brake Rod Support Strap 1*

Brake Return Spring4 CC 1787 Tab 2

Brake Rod Stop/Bolt Assembly

5 356 159 Damper Assembly (was SP 3608) 26 Suspension Spring: 2

CC 1857 5" (BLUE)CC 1746 6" (BLACK)CC 1747 6" (RED)CC 1927 6" (BROWN)CC 2970 6" (PURPLE)

7 CC 2660 Spring Compression Bolt 5/8" BSF 28 356 193 Spring Plate (was CC 1779) 29 Nut 5/8" BSF 210 CC 3887 Rebound Stop 5" Spring 2

356 162 Rebound Stop 6" Spring (was CC 3857) 211 CC 2843L Swinging Arm Assembly MK III LH 1

CC 2843R Swinging Arm Assembly MKIII RH 1CC 2835L Swinging Arm Assembly MKII LH 1CC 2835R Swinging Arm Assembly MKII RH 1

12 356 157 Nylon Bush (was CC 2326) 813 356 158 Sleeve (was CC 2376) 414 CC 2882 Bolt, Nut, Nyloc Nut /Washer 4*15 CC 2883 Brake Rod/Fork Assembly 216 CC 3529 Compensator c/w Grease Nipple 2*17 701 535 Compensator Pivot Bolt c/w Nut 218 377 433 Damper - Top Rubbers / Washer 219 377 434 Damper - Bottom Rubbers 220 556 295 Heavy Duty Washer 2*


{ }


P.C.D.

When ordering state diameterand pitch circle diameter of studs

10

1112

1314

15

1 2

3

4

5

6

7

8

9

8" 'BACK-UP' BRAKE/HUB ASSEMBLY


1 300 UNF 3/8" UNF Nut 82 2303 SC 3/8" dia. Spring Washer 83 Lockheed Backplates (See page 18/19). 14 305 UNF SS 3/8" UNF x 3/4" Set Screw 85 356 111 Wheel Stud M.12 x 115 (was CC 3394) 86 CC 3300 Brake Drum 27 356 106 Wheel Nut M.12 (was CC 3395) 88 SP 533 Split Pin 29 CC 3327 Slotted Nut 210 CC 3334 Grease Cap 211 CC 3328 "D" Washer 212 702 099/100 Outer Bearing (was CC 3326) 213 702 101/102 Inner Bearing (was CC 1015) 214 CC 3324 Oil Seal 215 CC 3331 Spacer 2

Page 14

REVERSING BRAKE FOR CARAVANS & TRAILERS

Brake shoe removal

Securely block the caravan wheels, loosenthe wheel nuts on the appropriate side andjack up the wheel. Lower the levellingjacks to steady the caravan. Fully releasehandbrake and remove road wheel. Lineup the hole in the brake drum with theslotted head of the micram adjuster. Backoff all brake adjustment with a suitablescrewdriver by turning the micram fullyanti-clockwise.

AP LOCKHEED

Release the pull-off spring (double coil)from behind the hook on the backplate,adjacent to the expander. At the oppositeend lift the carrier and shoe away from thespring abutment and disconnect the pull-off spring (single coil) from the leadingshoe web. This spring is identified, red forL.H. brake assembly and black for R.H.brake assembly.

Bearing

Grease retainer cap

Washer

Hub nut

Split Pin

Prise off the hub grease retainer cap andremove split pin, hub nut, washer andbearing. Withdraw the brake drum fromthe stub axle.

Take careful note of the spring andshoe positions.

Screwdriver

Brake drumMicram adjuster

Trailing shoeand carrier

Spring abutment

Pull-off spring(single coil)

Expander

Pull-off spring(double coil)

Note their positions and remove them.The double coil spring is not interchange-able with the one on the opposite brake.

Leading shoe

Springabutment

Micram adjusterand mask

Lift the leading shoe from the spring abut-ment and slide the adjuster and mask offthe expander body. Remove both shoesfrom the backplate. Slide the carrier as-sembly from the trailing shoe to exposeboth pull-off springs.


Shoe carrier

Trailing shoe

Pull-off spring(single coil)

Expander removal

Disconnect pullrod and remove rubberboot. Withdraw the expander assemblyfrom the backplate, push out the pivot pinand extract pullrod sub-assembly from theexpander body. Remove all dust and de-posits from the backplate. Do not blowout with an air line, it could be harmfulto inhale the dust, but remove with avacuum cleaner or wipe clean with a dampcloth. Do not use petrol or paraffin, if asolvent is necessary methylated spiritshould be used.

Inspection of parts

Carefully examine all component parts asdetailed under "Routine Maintenance" -3,000 miles or 12 months, servicing in-structions 1-4.

The brake shoe service operated byLockheed Brakes Division is the bestway of obtaining replacement Lockheedshoes to the correct specification. Toensure balanced performance, it is nec-essary to replace the shoes on bothbrake assemblies of an axle.

Expander replacement

Lubricate the pullrod sub-assembly withLockheed Expander Lubricant (Part No.LPK 103), fit into the expander body andinsert the pivot pin.

Fit the expander assembly onto thebackplate and check that it slides freely inthe slot. Pack the rubber boot withLockheed Rubberlube (Part No. LPK102), and slide over the pullrod up to thebackplate. Ensure that the boot lips locatecorrectly over the backplate tabs, and alsoseat into the pullrod boot groove.

Mask

Micram

Pivot pin Boot groove

Rubber bootPullrodsub-assembly

Expander body

Page 15


Brake shoe replacement

Using Lockheed Anti-Seize CopperGrease (Part No. LPK 104) lightly smearall metal to metal contact points such asbrake shoe and carrier tips, the abutmentfaces, the areas of the backplate againstwhich the shoe webs rest, also the surfaceof the carrier roller. Avoid contact of greasewith shoe linings, rubber parts and thefriction surface of the brake drum.

Assemble the new shoes, carrier andsprings by reversing the removal proce-dure. Ensure the carrier link locates ontothe spur on the trailing shoe web. Setmicram to minimum adjustment. After shoereplacement ensure that the carrier springsare correctly located. The outer spring iseasily seen, but the shoe and carrier shouldbe eased away from the backplate so thatthe inner spring can be felt to confirmcorrect positioning.

Note - the pull-off spring hook (doublecoil) is located into the slotted hole adja-cent to the leading shoe platform, also


See note Carrier link

Leadingshoe


Carrier spring(outer)Backplate

hook

ensure that the spring is behind the hookon the backplate.Carrier shoe location check

Near the heel on the trailing shoe web willbe seen a metal tab. Stamped into thecarrier in this area is an arrow marking.The shoe is correctly located in the carrierwhen these two line up exactly. Check theshoe action in the carrier by pushing theshoe against the carrier springs, whenreleased the shoe should freely springback to the marked position.

The tab and arrow position must alwaysbe checked through the hole in the

drum before brake adjustment is car-ried out.Ideally follow the caravan manufacturersinstructions concerning hub lubrication.As a general guide the bearing should beliberally coated with a good quality hubgrease .

Do not over pack the hub as this couldlead to contamination of the brake lin-ings.

Refit the drum, bearing, washer and hubnut. Tighten nut to the torque recommendedby the caravan manufacturer. Fit a newsplit pin and bend the ends over againstthe nut. Replace the hub grease retainercap.

Carry out the "Brake Shoe Adjustment"procedure, but remember to turn the drumin the forward direction only.

Brake shoe adjustment

Leading shoe

Carrier shoelocation check


Carrier spring(outer)


3 Align the hole with the micram ad-juster, then using a screwdriver turnthe slotted head fully c l o c k w i s euntil the drum will not turn. Slowlyback off the micram until the drumjust revolves freely. Turn the drumin the forward direction only dur-ing brake adjustment.

4 Important - Should the amount ofadjustment necessary seem exces-sive, recheck to ensure that thecarrier shoe is in the correct posi-tion, (see operation 2).

5 Replace the road wheel, tightenwheel nuts, release jacks and lowerthe vehicle to the ground. Repeatsequence for the opposite brake,then check for correct operation ofthe handbrake.

6 Adjust handbrake or overrun cou-pling pullrod if necessary, as de-tailed by the caravanmanufacturer.

Correct use of handbrake

Important.

Should the caravan be driven forwards upa slope and then require to be parked, thefollowing technique should be observed tooffer maximum security.

After applying the caravan handbrakefirmly, reverse the vehicle gently until thecaravan has moved backward slightly. Aclick from each brake may be heard, con-firming that the shoes have moved into thereverse position. If the handbrake wasnot fully applied initially, further movementof the handbrake will now be possible andfurther application should be made.

If it is found that no further movement of thehandbrake is possible, or that the caravanwill not move backwards, this would con-firm that the handbrake had been ad-equately applied in the first place.

Before adjustment the caravan should bebraked moving in a forward direction toensure that the carrier and trailing shoeare correctly positioned.(see operation 2).

1 Securely block the caravan wheels,loosen wheel nuts on the appropri-ate side and jack up wheel. Lowerthe levelling jacks to steady thecaravan, fully release handbrakeand remove road wheel.

2 Check for correct shoe position inthe carrier through the hole in thebrake drum, ideally using a torchor inspection lamp. The arrowstamped on the carrier must alignwith the metal tab on the shoeplatform.

Page 16

AP LOCKHEED

Routine maintenance

Owing to the varied use to which caravansare subjected it is difficult to specify routinemaintenance intervals. Some caravanswill be used weekly while others will bemoved perhaps two or three times a year.Therefore it is advisable to check the func-tioning of the brakes, i.e. handbrake op-eration or reversing etc., before every jour-ney on caravans which cover a low annualmileage. It is recommended that where acaravan does not achieve the 3,000 milesperiod then this service check must becarried out at least annually, ideally beforethe beginning of the holiday season.

Every 1,000 miles.

Check braking system operation, adjustas necessary.

Every 3,000 miles or 12 months (which-ever is the sooner).

Completely dismantle both brake assem-blies and carry out examination as follows.

1 Check thickness of the brake shoelinings which must never be al-lowed to wear down to the rivetheads. Replace shoes that are ap-proaching this condition, otherwisethe rivet heads may damage thebrake drum. Look for damaged,scored or cracked linings, also forany tendency for the linings to liftaway from the shoe platform. Re-newal is also necessary if the lin-ings are contaminated with hub lu-bricant irrespective of their state ofwear. To ensure balanced brak-ing it is important to renew theshoes on both brake assemblies.

2 Examine the fit and condition of therubber boots on the expanderpullrods. If perished, split, dam-aged or in a doubtful condition theyare best replaced. To vastly in-crease protection liberally applyLockheed Rubberlube (Part No.LPK 102) to the inside surface ofthe rubber boots.

3 Check all components in the ex-pander assembly for wear or dam-age, rectify as necessary. Whenthe expander is re-assembledsmear the metal parts withLockheed Expander Lubricant(Part No. LPK 103) and ensurethat it is free to slide in the backplateslot.

4 Thoroughly clean the drum withmethylated spirit or other recog-nised cleaning agents, then care-fully examine the friction surface. Ifseverely scored or rusty replacethe drum, otherwise light rustingcan be removed with fine emerypaper.

Lockheed brake lubricants

In order to maintain a high standard ofefficiency and reliability it is recommendedthat only genuine Lockheed lubricants areused with Lockheed brake equipment. Thelubricants listed below are available fromLockheed stockists.

Rubberlube Expander LubricantAnti-Seize Copper Grease10 gram sachet - LPK 10210 gram sachet - LPK 10310 gram sachet - LPK 104454 gram tin - LPK 94454 gram tin - LPK 93

BRAKE ASSEMBLY COMPLETE R.H.LG 15050 L.H. LG 15051


Page 17


7 812

5

2

10

111

9 6

43

SERVICE REPAIR KITS AND THEIR CONTENTS


Page 18

IMPORTANT NOTE:

Pages 15, 16, 17, 18 and 19 refer to Lockheed Backplates and Components. These were never B & B parts.

All spares should be obtained from A P Lockheed or their agents.

USE ONLY GENUINE LOCKHEED REPLACEMENT PARTS DURING OVERHAUL.

If in doubt contact:-Automotive Products plc., Lockheed Brakes Division, Tachbrook Road,Leamington Spa, Warks. CV31 3ER. England.Tel:(0926) 470000 Telex: 311571 AP PLCG Facsimile:(0926) 472000A BBA Group Company.

AP LOCKHEED

Page 19

DESCRIPTION KIT PART No No KIT CONTENTS QTY

Backplate R.H. LPP 113 1 Backplate R.H. 1

Backplate L.H. LPP 112 1 Backplate L.H. 1

Expander Assembly R.H. LQ 15649 2 Expander R.H. 13 Rubber Boot 1

Expander Assembly L.H. LQ 15650 2 Expander L.H. 13 Rubber Boot 1

Rubber Boot LPP 114 3 Rubber Boot 2

Micram Adjuster LK 17053 4 Mask 15 Micram 1

Brake Shoes (Axle set) LS 1263 6 Leading Shoe 27 Trailing Shoe 2

Trailing Shoe Carrier LPP 115 8 Trailing Shoe Carrier 1

Spring Kit (Axle set) LK 17054 9 Pull-off (Black) Single Coil R.H. 19 Pull-off (Red) Single Coil L.H. 110 Pull-off Spring Double Coil R.H. 110 Pull-off Spring Double Coil L.H. 111 Carrier Link 212 Carrier Spring 4


CORNER LEGS (STEADIES)

105

6

7

13a

5

26

CC3560

CC2330

6

73

2

15

13

76

5

912a

2

11

8a3

4

2

8

4

5

109

12

7

PART PART NO. DESCRIPTION OF PART QTY

2/3 319 UNF/300B 2 1/2" x 3/8" UNF Bolt and Binx Nut 12/4 315 UNF/300B 2" x 3/8" UNF Bolt and Binx Nut 15/6 CC 602/CC 2762 Circlip and Pivot Pin 17 CC 2335 Side Arm 18 CC 2333 Leg (2330 Corner Steady) 1*8a CC 2337 Leg (CC 3560 Corner Steady) 19 CC 591 Mills Pin 110 CC 185 Washer 111 CC 4693 Nut 112 CC 2332 Screw (length 15 1/2") (CC 2330 Corner Steady) 112a CC 651 Screw (length 17 3/4") (CC 3560 Corner Steady) 113 CC 2331 Base Plate (CC 2330 Corner Steady) -*13a CC 3893 Base Plate (CC 3560 Corner Steady) -*15 CC 2338 Wing Nut 1*


Page 20

11a

2

3

4

57

9

10

1314

15

13 11

6

87

PART PART NO. DESCRIPTION OF PART QTY

1 356 650 Insert Cap 11a 356 649 Starloc Washer 12 356 651 Rubber Knob 13 CC 926A Handle 1*4 CC 589 Grooved Pin 15 700 625 Washer (was CC 692) 16 CC 2191 Outer Tube 1*7 CC 977A Thrust Washer 28 356646 Ball Race (Was CC826) 19 CC 627 Screw 1*10 - - -11 CC 3404 Fork Assembly 112 - - -13 CC 3198 Wheel Clip 214 CC 3196 Spindle 115 CC 3197 7" Wheel 116 356 813 Pressure Pad (See Page 8 , item 5) 117 CC 3506M Jockey Wheel Clamp Handle (See Page 8, item 10) 118 CC 632A Heavy Duty Cast Clamp (Not Shown) 1

HEAVY TELESCOPIC JOCKEY WHEEL CC 3850

N.B. The "light" telescopic jockey wheel assembly (CC 1073) exterior shaft diameter 1' 3/8"(36mm) is no longer available but used the same 7" wheel (CC 3197) spindle and clips.


12

N.B. Exterior Shaft diameter 1' 5/8" (42mm).

}

Page 21

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