Bleeding brakes with ABS

[fubar]

Hello all I think this is my first post and need advice .. I had the misfortune last year of air getting into ABS pump when replacing a corroded brake pipe on a Ford Galaxy Mk1, despite using VCDS to actuate the motors/servos inside the pump to bleed them I ended up scrapping the car though it wasn't worth much. I have as a result lost a bit of confidence with brake hydraulics on my VX80 + 150k miles (New discs and pads have left pedal response feel like there is air in the system even though have bled the corners extensively and clear and driven 200miles to bed in the pads want to treat my 80 to a brake overhaul as I frequently tow a twin axel caravan - sorry lol!)

I have a few concerns now if anyone can help please;
I am worried about bleeding the system and the effect on the ABS pump if I replace the brake master cylinder and the whole system needing to be bled, will ABS pump get air in it and be unbleedable? or if needed disconnect one or both batteries (reluctant)

What is the biggest pitfall of using a seal kit versus new or remanufactured calipers, do you flush the caliper fluid-ways in case of grit ingress?

looking at the trend of other owners are doing;
Bigg Red for seal kit seems popular
Roughtrax for Calipers but a massive £500 for a full set though there are other suppliers

grateful for help
thanks

 

[Shayne]

Had mine rebuilt by big red the standard option more or less gives you new calipers at half the price .

I had similar concerns over bleeding as it was my first attempt at a 4 wheeler and the tip i found to be most useful is to begin by topping up the reservoir putting your foot on the brake , stopped at lights kind of thing not emergency braking pressure and start the engine . The pedal will sink giving some confidence there is fluid in the top of the system before you start to bleed .

 

[fubar]

thanks Shayne, is that for the new MC? the top end of the hydraulic system will still have air and that may make its way to the ABS unit, unless theres a way to isolate the MC for easy bleeding, ive read about bench bleeding ..

 

[Shayne]

As i said i'm not they guy to advise you but i had the calipers off for a week so i would guess the system was drained dry but i didn't change the master .

Mines a 90 series which has abs and the same brakes as the 80 i think , the above worked fine for me .

 

[flint]

As Shayne said, the Big Red rebuild sounds like a good deal and I’m sure that they’ll let you know if the calipers are unserviceable. If you’re not working on the ABS pump itself, it shouldn’t be necessary to disconnect the batteries, just don’t turn on the ignition before you're finished and pump the pedal several times to relieve any pressure left in the system. If you are worried about air in the ABS pump, I've not had trouble with this, but I've read that one way is to bleed as normal and then find a gravelly or otherwise slippery road or track and, if safe to do so, brake hard a few times so that the ABS kicks in. Then bleed the brakes through again. Means bleeding twice, but should help get rid of any residual air.

 

[Towpack]

I flushed and bled the whole brake system on my 80 a while back with no ABS issues at all. I even inadvertently completely emptied one side of the reservoir and it still bled easily when I refilled with fluid. I used the easibleed pressure bleeder which made light work of the task, as do the other vacuum devices that suck the fluid through the nipple rather than forcing it through from the other end. The FSM gives no special instruction relating to ABS when bleeding the system.

 

[Dave2000]

If you replace the master you will need to bleed the entire system, including the load sensing valve above the rear axle. I recently replaced everything on my 80's brakes except the pipes and load sensing valve which is still to be done, and I did (perhaps still do?) have air that was/is difficult to shift. I used all new parts and not rebuilds. I recognise that many have had success going this route, but many also have had problems, often within a couple of years of the work being done, if you go the rebuild route, the info gleaned from who's good and who to avoid abounds, so do your research.

Re bleeding, I have plenty of experience with braking systems but found the 80 more of a challenge than most. I bled with the traditional pedal method, and used the pressure bleeding method, and even activated the ABS forcefully and 'think' the pedal feel improved. It does seem that it (the air) gets shifted a little at a time, why it has been such a pain I do not know? I am now coming to the conclusion, that perhaps the master cylinder which was bought for a customers car (but not used) perhaps is faulty, it did sit on a shelf for at least a couple of years, but was stored in a plastic bag with a 'moisture grabber'. So my techniques may not be flawed but have a faulty part???? YMMV.

Oh, and welcome.

regards

Dave