Confuzzled With My Brakes

[welshpug 1,657]

Right, i'm getting really frustrated with my Mi16 (405 )

 

basically the MOT picked up pitted rear discs as well as low efficiency on the parking brake, I noticed the fronts were low too.

 

I had spares for the front, and Paul kindly sold me the complete setup off his sorrento (calipers and recent pads and discs)

 

Front calipers were pretty good, all went on fine up there, pistons pushed back fairly easily by hand.

 

On the rear I though it would be easier to just swap the whole setup, and to overhaul the original calipers at a later date, I clamped the flexis, swapped the calipers (after winding them back a turn) fitted the discs and pads then proceeded to bleed the system.

 

I used a non return valve and my brother pumping the pedal at my instruction, didnt take long for either side.

 

 

now comes the problem, the pedal went to the floor with a little resistance, no leaks or loss of fluid I was advised by my local garage that the seals in the M/C would be the likely culprits so I have fitted a new unit, bled the system again, hardly any air coming out, but as soon as I try to move the car the pedal sinks, though it does now stop the car, allbeit nowhere near as well as it should

 

 

the abs light is on too, so i changed one sensor which I knew had a dodgy wire, and cleaned all the trigger rings (full of grease at the front and iron fillings at the back) but its still on and I dont know if I need to clear a fault or something???

 

 

HELP!!!!

 

 

(its going in to the garage Tuesday for this and the MOT, but anything I can do to help them along saves me a bit of cash)

[inferno 1]

are you losing fluid? is the abs unit leaking? ive never used a non return valve to bleed with, r they good?do u need to bleed the mc before fitting it? im sure u do on some cars.

[welshpug 1,657]

cant find any leaks adn i'm not losing fluid.

 

cant figure how the hell you'd bleed the m/c before fitting it!? theres no fluid in there before fitting!

 

non return valve is just to stop the air and fluid from returning into the pipes as youre trying to close the nipple.

Edited March 17, 2007 by welshpug

[pug_ham 244 3 Cars]

cant figure how the hell you'd bleed the m/c before fitting it!? theres no fluid in there before fitting!

From the pipe fittings at the m/c?

 

Bleeding an abs system can be a nightmare, if you changed the m/c then you should've got air out of the system.

 

Its quite possible that air is getting trapped in the abs accumulater giving you false indication when bleeding. You need a very high pressure to properly bleed an ABS system so the two man method won't work imo, even an ezi-bleed would struggle to do it correctly.

 

Graham.

[welshpug 1,657]

i did bleed the abs unit but I didnt get much air from it at all (its the first thign after the m/c and its downhill so fluid loss would have been negligable.

 

I tried bleeding the system using a pressure bleeder but nothing at all comes out of the calipers, only when I pump the pedal, though I didnt try the ABS unit's nipples.

 

I also cant see why an ABS system would need a higher pressure to bleed it as its an "additional" system and nothing should be active with the ignition off??

[t16ryan 1]

did you try it with the engine running? are the fronts efficent enough?

[welshpug 1,657]

did you try it with the engine running? are the fronts efficent enough?

 

thats a new one on me! dont know how having the engine on would affect how the bleeding would work? bar the abs system getting really confused!

 

I darent drive it any more than to park it so I don't know how well they work, though a good yank on the handbrake does slow it down quite well so that issue raised by the MOT has been addressed

[mi16nut 0]

I've no experience of bleeding ABS systems, but did you bleed the rear calipers off the car or on?

 

As the bleed nipple is not at the top when mounted on the car, air gets trapped there & you'll never get a firm pedal. Might not be your problem, but could be worth a go if not already done?

 

Mark.

[t16ryan 1]

thats a new one on me! dont know how having the engine on would affect how the bleeding would work? bar the abs system getting really confused!

 

I darent drive it any more than to park it so I don't know how well they work, though a good yank on the handbrake does slow it down quite well so that issue raised by the MOT has been addressed

 

I have had it with a coupl eof old cars and a black GTi i had with ABS was a nightmare bleeding up, but with the engine running, just hold the peddle down and should com out constant and fast,

[welshpug 1,657]

I've no experience of bleeding ABS systems, but did you bleed the rear calipers off the car or on?

 

As the bleed nipple is not at the top when mounted on the car, air gets trapped there & you'll never get a firm pedal. Might not be your problem, but could be worth a go if not already done?

 

Mark.

 

 

all bleed nipples on this setup are on the top of each component the flexi's to the calipers were clamped, the bleed nipple opened, then pressure put ion the pedal before releasing the clamp, so in theory no air should have entered the system, but I have still bled quite a lot of fluid out to no avail.

[pug309twin40s 1]

sounds like you have air trapped in the system somewhere. It can take quite abit of bleeding sometimes to get all the air out the system.

 

I take it you've put new brake fluid in after replacing the master cylinder. Does new fluid come out from each bleed point on all calipers and the ABS unit?

[Miles 331 1 Cars]

I know that it was quite common to take the rear calipers off the 405 as the nipple at the bottom of it and you couldn't get all the air out, Having ABS should make no differance when bleeding as the pedal action will go thru the module, Worth bleeding that off without a doubt thou

[pug_ham 244 3 Cars]

I also cant see why an ABS system would need a higher pressure to bleed it as its an "additional" system

Isn't it a series of valves that can all trap any air inside thus making it harder to bleed, higher air pressure or not?

 

The 405 Haynes manual has a remarkably different bleeding procedure for the rear calipers compared to a 205, maybe try the method in there & see if that imnproves it at all.

 

Graham.

[welshpug 1,657]

garage said seized load compensator, hence the difficulty in bleeding DOH! they said even their power bleeder didnt get much out at least it wasnt my fault

 

And the fault they read on the ABS is a relay, which I can see as being expensive