Front brake hoses

From French Car Wiki
Jump to: navigation, search

Go to Xantia Wiki Homepage

INTRODUCTION

Front brake hoses are a common cause of MoT fails or advisories. It's not a difficult or even messy job if you do it the right way.

TOOLS

  • 8mm deep(ish) socket to undo and tighten the bleed nipples - nothing else will do; you have been warned!
  • 8mm ring spanner to open/close the bleed nipples
  • 12mm ring spanner for pressure release valve
  • 11mm gland nut spanner (gland nut on inboard pipe into female hose end)
  • 14mm gland nut spanner (hose male end into calliper)
  • Mole-grips
  • Sharp knife
  • Hose clamp,
    Brake Hose Clamp
You can make one from 2 bits of hardwood about ½" x ¾" and 3" long, a couple of small coach-bolts, nuts and washers to fit. Take the sharp corners of the bit that clamps the hose for those occasions when you need to clamp a hose that don't want to have to replace!
  • Xantia brake-bleeding kit:
    Brake Bleeding Kit
1. Bleed Bottle
Plastic 500ml drink bottle with clear polythene pipe sized for the brake nipples that goes to bottom of bottle, a much shorter second pipe only just goes through the lid (to suck/blow LHM in/out of bottle). Both pipes are a tight fit through holes drilled in lid so that the bottle can be used to suck LHM out of the reservoir.
2. Cheap 500ml cook's plastic measuring jug
used (only half full) for topping up the reservoir with LHM.
3. 2L plastic ice-cream tub or similar
for LHM-y waste and, with a lid, doubles as leak- and dirt-proof storage for the kit.


PARTS & CONSUMABLES

  • Pair of brake hoses - you'll probably find two lengths quoted, 385mm and 400 (or 402), the shorter one is correct for all Xantias except those with the biggest (288 x 28mm) front discs: S1 - only V6; S2 - HDi 110 & V6, plus 2.0 CT & 2.1 TD after RP 8001. However, as the longer ones are exactly the same except for the slight increase in length, there is no problem in using them on on any Xantia - and they often are!
  • Quality kitchen roll (the cheap stuff tears too easily and doesn't mop up so much)
  • PlusGas or similar penetrating fluid.
  • LHM - 1L should be plenty.


METHOD

SAFETY WARNINGS: If the car falls off the supports while your head is under the wheel arch, it's likely to break your neck.  The handbrake operates on the FRONT wheels.
  1. Chock the back wheels very securely.
  2. Slacken the front wheel bolts slightly.
  3. Raise the suspension to HIGH;
    with the engine idling, move the Height Control Lever (between the front seats) to its rear-most (HIGH) position and wait until the car has stopped rising.
  4. Support the car very securely with axle stands under the front jacking points.
  5. Lower the suspension
    (Carefully! as this will lift the front of the car further) by moving the suspension control lever forward one position at a time to the forward-most position, LOW.
    Release valve.jpg
  6. De-pressurise the hydraulic system, by undoing the release valve (12mm hex arrowed in top photo - seen from underneath) no more than ONE turn with the engine still idling.
  7. Switch off the engine.
    Brake Hose new.JPG
  8. Remove front road wheel on one side.
  9. Pop the rubber cap off the bleed nipple
  10. Squirt PlusGas onto bleed nipple and the connection on each end of the hose - make sure that you get plenty on the inboard gland nut
  11. Check that the new hose is the same as the old one!
  12. Clamp the old hose several inches above calliper
  13. Clean the calliper around hose boss to avoid dirt getting into the calliper when the hose is undone.
  14. Cut the old hose just above the calliper.
  15. Unscrew old hose from calliper (14mm),
    Brake Hose M-end.JPG
  16. Cover the inboard (female) end of new hose;
    either tear a finger out of a disposable vinyl glove and fit it over the end to keep the muck out, or if the hose comes sealed in a plastic bag, just tear open one end enough to push out the 14mm end of the hose leaving the rest of the hose in the bag.
  17. Screw new hose into calliper and do up tight with gland-nut spanner (3rd photo)
  18. Put a wad of kitchen roll beneath the inboard joint to soak up the LHM that will dribble out.
  19. Undo the inboard joint ;
    Brake Hose F-end.JPG
    undo the 11mm gland nut behind the bracket (4th photo) through which the metal hose-end fits. Then grab the hose-end with mole-grips and wrestle it out of the bracket.
  20. Clean the bracket and gland nut to avoid crap going down the new hose into the calliper
  21. Fit inboard end of new hose into the bracket after removing the 'protection' from the hose end.
  22. Do up the 11mm gland nut:-
    Push it against the spring-steel (anti-rattle) shim while holding the hose firmly in the bracket. Start the thread by hand to make sure it's not cross-threaded then do up tight (not too tight) with 11mm gland-nut spanner.
  23. For the other side repeat steps 8. through 22. above.
  24. Bleed the front brakes thoroughly (see separate guide).
    Fresh LHM is bright green, but greenish-yellow is the best you can expect if the hydraulic system hasn't been flushed and refilled with new LHM in the last 3-4 years. Bleed until the fluid is at least clean and free of bubbles.
  25. Wipe up all LHM spillage - so any leakage will show up.
  26. Pressure test the hose joints (and bleed nipples)
    by pushing hard (ONCE ONLY) on the brake pedal for 10 seconds or so and then inspecting the joints and nipples for any weeps.
  27. Reverse steps 6. through 1. above.
  28. Road-test the car.
    If the brakes 'hesitate' at all, there's air in the hydraulic system; bleed the front brakes again. If, after the car has been standing over-night, the STOP light takes more than about 10 seconds to go out or the brakes 'hesitate', a sphere is probably going flat and leaking gas into the hydraulic system.