SHY 7G Posted October 25, 2013 Share Posted October 25, 2013 On my rebuild I am fitting Lockheed brake calipers that have both a primary and secondary brake line supply's. The problem is which is which on the caliper itself? Quote Link to comment Share on other sites More sharing options...
bushwhacker Posted October 25, 2013 Share Posted October 25, 2013 Hi Not wanting to hi jack your post. I am about to clean my calipers and fit new seals mine are L/heed also. I was going to post as to which of the three bleed nipples to do first????? With the pistons out you can check which hole supplies which pistons. I was just going to stick a brake line in each hole on the caliper and bleed it. Or does it matter ????? Quote Link to comment Share on other sites More sharing options...
Phil Hancock Posted October 25, 2013 Share Posted October 25, 2013 The pressure in is the 2 close together ports marked on the r/h, other ports are either plugged or have bleed nipples. Quote Link to comment Share on other sites More sharing options...
bushwhacker Posted October 25, 2013 Share Posted October 25, 2013 Yes the 2 marked are indeed the supply but what about the 3 bleed nipples. Which order when bleeding? Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted October 25, 2013 Share Posted October 25, 2013 Haynes has this information.... It's very specific, and needs following to the LETTER... Think this is the same, but it is from memory I am checking it: http://c7743.r43.cf2.rackcdn.com/Downloads/instructions/abs_brake_bleed_rrc.pdf Quote Link to comment Share on other sites More sharing options...
bushwhacker Posted October 25, 2013 Share Posted October 25, 2013 I think I will sit back and see if any more info comes up as I don't have ABS to worry about. Fingers crossed. Quote Link to comment Share on other sites More sharing options...
SHY 7G Posted October 28, 2013 Author Share Posted October 28, 2013 On my rebuild I am fitting Lockheed brake calipers that have both a primary and secondary brake line supply's. The problem is which is which on the caliper itself? All very interesting and very helpful but any idea's which is primary and which is secondary?? If anyone come's across the answer in Haynes etc etc please post.... cheers Rich Quote Link to comment Share on other sites More sharing options...
Stevie D Posted November 6, 2013 Share Posted November 6, 2013 From Rave - Describes which calipers pistons do what... Brake calipers - front - (5) rear - (6) NOTE: To identify separate hydraulic circuits, they are referred to as HYDROSTATIC and POWER circuits. Power circuit - Consists of rear calipers and upper pistons in the front calipers, supplied by direct hydraulic power from power valve. Hydrostatic circuit - Lower pistons in the front calipers form this circuit, supplied with hydraulic energy from servo cylinders comprising a combination of master this is the bleed order for an ABS equiped truck... 5. Bleed four front caliper lower (hydrostatic) bleed screws in the conventional manner. In the order: outer bleed screw driver’s side, opposite caliper outer bleed screw, inner bleed screw, inner bleed screw driver’s side. Depress brake pedal slowly and progressively, locking bleed screw at bottom of each stroke. 6. Bleed hydraulic pump - open bleed screw on pump and allow fluid to flow until clear of air bubbles. Do not use bleed bottle, use a clean absorbant cloth to prevent fluid spillage. And for an non abs truck... The hydraulic system comprises two completely independent circuits. The rear calipers and lower pistons in the front calipers form the secondary circuit, while upper pistons in the front calipers form the primary circuit. The following procedure covers bleeding complete system, but it is permissible to bleed one circuit only if disconnection is limited to that circuit. Bleeding will be assisted if engine is run or a vacuum supply is connected to servo. WARNING: If engine is running during brake bleeding process ensure that neutral or park is selected in main gearbox and that park brake is applied. When bleeding any part of secondary circuit, almost full brake pedal travel is available. When bleeding primary circuit only, brake pedal travel will be restricted to approximately half. NOTE: When bleeding system commence with caliper furthest from master cylinder. Finally tighten bleed screws to 10 Nm. Bleeding 1. Fill fluid reservoir with correct grade of fluid. See LUBRICANTS, FLUIDS AND CAPACITIES, Information, Recommended Lubricants and Fluids NOTE: Maintain correct fluid level throughout procedure of bleeding. 2. Connect bleed hose to bleed screw on rear caliper furthest from master cylinder. 3. Submerge free end of bleed hose in a container of clean brake fluid. 4. Loosen bleed screw 1/2-3/4 of a turn. 5. Operate brake pedal fully and allow to return. NOTE: Allow at least five seconds to elapse with foot right off pedal to ensure pistons fully return before operating pedal again. 6. Repeat 5 until fluid clear of air bubbles appears in container. Keeping pedal fully depressed, tighten bleed screw. 7. Remove bleed hose, replace dust cap on bleed screw. 8. Repeat 1 to 7 for other rear caliper. 9. Remove front wheel furthest from master cylinder 10. Connect a bleed hose to primary bleed screw on front caliper. 11. Connect a bleed hose to secondary bleed screw on same side of caliper as primary screw. 12. Repeat 3 to 7 for front caliper, bleeding two screws simultaneously. 13. Connect a bleed hose to other screw on front caliper furthest from master cylinder. 14. Repeat 3 to 7 for second secondary screw on front caliper. 15. Refit front wheel. 16. Repeat 9 to 15 for front caliper nearest master cylinder. It seems to illustrate the top outboard screw is the primary circuit (10) and the two 'front' mid posn screws as the secondary (11 & 13) Sorry it doesn't copy and past the illustrations. Now i'll erturn to my disco ABS search - if anybody knows how to fix my disco ABS I'll be gratefull lol. It's quite different. :-) Steve Quote Link to comment Share on other sites More sharing options...
220890rmac Posted May 17, 2014 Share Posted May 17, 2014 Hi there, unsure of what ports are primary and secondary on the caliper itself if someone could shine some light please. Thanks Quote Link to comment Share on other sites More sharing options...
Landowner Posted May 18, 2014 Share Posted May 18, 2014 Do they have primary and secondary? I always thought that they were dual circuit, meaning that it doesn't matter which is connected to which, when one fails then the other does the job. There are two separate chambers in the caliper and each supplies two of the pistons (one either side) so it wont matter which port the pipes are connected to, both will be the same capacity and operate in case (or in spite of) of a failure in the other Quote Link to comment Share on other sites More sharing options...
bushwhacker Posted May 18, 2014 Share Posted May 18, 2014 Landowner I believe what you saying is correct. I was able to put mig wire through each hole and see where they came out. So I just connected the 2 fluid lines one to each hole, bled the three nipples and the brakes work as they should. Quote Link to comment Share on other sites More sharing options...
Adversane Posted July 5, 2022 Share Posted July 5, 2022 You do need to get the pipes in the right holes. If you don’t then you won’t be able to bleed the system. To check after you have installed the pipes open the nipple on the outside of the calliper and ignition off press the brake pedal. If you don’t get fluid or can’t get pedal down you have them the wrong way round. if you open to top nipple and ignition off press the pedal and get fluid that also shows they are the wrong way round. Quote Link to comment Share on other sites More sharing options...
blz6662 Posted August 23, 2022 Share Posted August 23, 2022 Hi, Please follow the attached from the manual. Works every time. If you are vacuum bleeding then no problem, always done it this way without any issues. Cheers blz6662 range rover classic non abs brake bleeding.pdf Quote Link to comment Share on other sites More sharing options...
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