brake bleeding problems.

[steve_k]

afternoon folks, looking for some advise.

over the past few days i've done a complete brake overhaul & upgrade on my mates e30.

here's what was done/fitted.

front.
hi-spec 4 pot calipers,
ds3000 pads, 284mm x26mm discs.
braided steel lines.
all new hard lines (cunifer).
clio servo.
vw t4 25mm non abs M/C.
twin pot remote brake fluid reservoirs.

middle.
willwood adjustable bias valve.
one piece braided steel line to a brand new T piece,

rear.
one piece braided steel line from the T piece to the caliper.
fully rebuilt tourer rear calipers.
new discs & ds2500 pads,

all unions are stainless steel.

the above is exactly the same set up as on my sport.

now here is the problem,
when i finished fitting all the above i filled the system up pumped the brake pedal a few times to get it in the lines,

i then left the car with the brake pedal held down over night as i always have to keep pressure in the system.

came to bleed the brakes today, left the brake pedal held down & check all round for any leaks (none found) undid the rear drivers side bleed nipple & had a little spurt/dribble out of it, did it back up, checked all the others but they were bone dry,

seeing as i was on my own i went to use a gunson eezibleed system,
tried this but still nothing, all i'm getting is a little spurt then dribble from the drivers side rear caliper.

checked all the unions are tight & there's no kinks in the lines,

so does anyone have any idea what it could be??

[flybynite]

My experience on my E30 was of a non-ABS system which is much easier to bleed. From experience on other cars getting it through the ABS block is often the problem. When you are doing it t'old fashioned way, you have to pump the brake a lot more before each bleeder release with ABS.

I think the few pumps you gave it may not have been enough to prime the ABS block (just guessing here).

Never used the Gunson, are you sure it had enough pressure? should be above 10psi less than 20psi I tend to either use one connected to the airline or a bigger pot with a gauge as some newer cars are picky with the bleeding pressure through the ABS.

[steve_k]

i've bleed non abs e30's a few times & they are so much easier to bleed,

been looking at it this afternoon & tried pumping it till my leg was sore (then swapped legs & pumped again), when from the back of the car forwards checking each union for any fluid,

looks like the abs pump is the culprit, spoke to my mate (the owner) & he says if need be pull the abs pump & re-plumb the lines as the his car never had abs & it was fitted before he got it.

so looks like that is the plan of attack.

as for the gunson, if i use it i normally have the pressure at 15-18psi, but like you say some systems can be very picky.

[paultv]

If you have air in the ABS, you need to trigger the ABS unit as you bleed with pressure behind it - you can do this with simple wiring, a couple of cables - I wrote a "How to" ages ago -
see if I can find it - too much wine tonight!

Paul

[steve_k]

If you have air in the ABS, you need to trigger the ABS unit as you bleed with pressure behind it - you can do this with simple wiring, a couple of cables - I wrote a "How to" ages ago -
see if I can find it - too much wine tonight!

Paul

cheers for that paul, i think it could have air in the abs system,
if you could find that "how to" that would be fantastic.

[flybynite]

The ABS block is usually the culprit, most things these days you plug the laptop in and run the bleeding sequence to fire the ABS. Firing the ABS should work with the E30, but don't think it should be necessary.

FWIW both Bently and Haynes say the same thing if you have ABS, to pump 12 times then close at the bottom as usual. (that is doing it the 2-man way)

With a pressure bleeder, one of the old manuals says:

"On models equipped with this device (ABS) it is recommended that the pressure bleeding system is used. Have an assistant depress the pedal and hold it down. Open the right rear bleed screw, release and depress the brake pedal 12 times fully, hold the pedal down, then close the bleed screw. Repeat this procedure on the left rear, front right, front left in that order.

The manual brake bleeding procedure is as for a brake system without ABS but include the 12 strokes of the pedal as just described.

Worth a shot?

[steve_k]

The ABS block is usually the culprit, most things these days you plug the laptop in and run the bleeding sequence to fire the ABS. Firing the ABS should work with the E30, but don't think it should be necessary.

FWIW both Bently and Haynes say the same thing if you have ABS, to pump 12 times then close at the bottom as usual. (that is doing it the 2-man way)

With a pressure bleeder, one of the old manuals says:

"On models equipped with this device (ABS) it is recommended that the pressure bleeding system is used. Have an assistant depress the pedal and hold it down. Open the right rear bleed screw, release and depress the brake pedal 12 times fully, hold the pedal down, then close the bleed screw. Repeat this procedure on the left rear, front right, front left in that order.

The manual brake bleeding procedure is as for a brake system without ABS but include the 12 strokes of the pedal as just described.

Worth a shot?

i completely forgot about my bentley manual

will give that a try & see what happens,

[paultv]

I found what I wrote up a couple of years ago - but it needs some pictures, I'll try and add them today.

https://bmwe30cabriolet-wdm.blogspot.co ... r-abs.html


Paul

[steve_k]

I found what I wrote up a couple of years ago - but it needs some pictures, I'll try and add them today.

https://bmwe30cabriolet-wdm.blogspot.co ... r-abs.html


Paul

fantastic thanks for that bud i'll have a read through it,
will be tackling this issue either today or tomorrow depending on the weather.

[paultv]

I've added a few photo's and a schematic to help make this post a bit clearer - Bosch state that you should run the pump and solenoid for 30 seconds, then allow to cool before moving to the next solenoid.

https://bmwe30cabriolet-wdm.blogspot.co ... r-abs.html

Paul

[steve_k]

I've added a few photo's and a schematic to help make this post a bit clearer - Bosch state that you should run the pump and solenoid for 30 seconds, then allow to cool before moving to the next solenoid.

https://bmwe30cabriolet-wdm.blogspot.co ... r-abs.html

Paul

the pictures are ideal, thanks for that gives me an idea what to make to get it done,

[steve_k]

if i was you i'd be asking the team on here to make that "how to" a sticky in the tech section as it could come in handy for other folk.

[paultv]

I just stuck a tiny video clip on there so you can hear what it should sound like when everything is activated - basically as it sounds when the ABS runs as you skid towards that tree
on a wet Monday morning!!

Paul

[steve_k]

I just stuck a tiny video clip on there so you can hear what it should sound like when everything is activated - basically as it sounds when the ABS runs as you skid towards that tree
on a wet Monday morning!!

Paul

nice one, as the ad says "every little helps",

as for skidding towards the tree? in my case it was a hedge on a snowy Sunday

[paultv]

[martauto]

if i was you i'd be asking the team on here to make that "how to" a sticky in the tech section as it could come in handy for other folk.

I will do that mate now I`m off the late shift.

Mart.

[steve_k]

if i was you i'd be asking the team on here to make that "how to" a sticky in the tech section as it could come in handy for other folk.

I will do that mate now I`m off the late shift.

Mart.

nice one cheers mart

[steve_k]

i was coming round a corner on a country lane (slowly) only to find a tractor on the wrong side of the road heading my way, bush or tractor??

[paultv]

BUSH!!!

[steve_k]

BUSH!!!

exactly, better to sacrifice a wing than the whole car.

[steve_k]

well i tried that how to of your paul,

i used a spare battery as i didn't have enough wire to reach to the boot (battery in boot),
yet there was no apparent sound coming from the abs pump,

had to stop shortly after as there was a nice big leak from the hard line/braided steel flexi on the front left side, (my fault for flaring the end instead of bubble flaring, can't change it till i gt some more brass unions on monday), which leads me to believe that the fluid is getting through the pump,

just to check i undid the union from the abs pump to the front left line, sure enough it was wet.

looks like the problem could have been the leak at the front left so i'll repair/replace that on monday & try bleeding the brakes the normal way again but if i need to i'll use your purge method again.

still can't understand why there was no noise/sound from the pump when i applied power to it though, ,akesme wonder if the pump has packed in altogether???

[martauto]

if i was you i'd be asking the team on here to make that "how to" a sticky in the tech section as it could come in handy for other folk.

I will do that mate now I`m off the late shift.

Mart.

Sorted guy`s.

Mart.

[steve_k]

if i was you i'd be asking the team on here to make that "how to" a sticky in the tech section as it could come in handy for other folk.

I will do that mate now I`m off the late shift.

Mart.

Sorted guy`s.

Mart.

nice one cheers mart

[paultv]

Just check you have a good earth if you're using an extra battery - strap the negative to an earth point under the hood - suspension tower nuts are the best - then a positive feed to pin 30 of the 4 pin relay socket, ( nearest the wing ) this is for the pump, it should run immediately.

PS. IMPORTANT - Don't do any work on the ABS without first removing the multi pin connector for the ABS ECU - it's sensitive and can be fried with great ease.

Sounds like you have fluid leak problems fix first - I have a new Master and Slave clutch set to instal as well ..... I've done the slave before, but never the master.


Paul

[steve_k]

Just check you have a good earth if you're using an extra battery - strap the negative to an earth point under the hood - suspension tower nuts are the best - then a positive feed to pin 30 of the 4 pin relay socket, ( nearest the wing ) this is for the pump, it should run immediately.

PS. IMPORTANT - Don't do any work on the ABS without first removing the multi pin connector for the ABS ECU - it's sensitive and can be fried with great ease.

Sounds like you have fluid leak problems fix first - I have a new Master and Slave clutch set to instal as well ..... I've done the slave before, but never the master.


Paul

thanks for that will give it another try tomorrow,

[steve_k]

well i finally got round to trying your method paul, (been laid up with a dislocated knee for a few weeks)

& the outcome is it looks like his abs pump has seized,
the fluid is going into the abs pump but none is now coming out the other side,

at first thought the seals had gone in the M/C due to using the pressure bleeder, took the M/C off & bench bleed it, all worked fine, so made up a couple of new lines direct from the M/C to each corner & surprise surprise, fluid came out each corner using the two man method.

so i've given him a choice, either source a new or known working 2nd hand abs pump, or remove it all together.

just waiting to se what he comes back with.

[paultv]

Sorry to hear about the knee - nasty!

Yes, it does sound like the filters are blocked restricting fluid flow - to test the ABS on the bench you should be able to feed fluid into the Front L and R inputs and get fluid out of the respective outputs - and the same with the single rear input should pass fluid out the rear output.

I tested mine with cheap suringes connected to brake pipe stubs - you should be able to push the fluid staight through without a lot of pressure - this indicates clean -ish filters - I've had ones totally blocked.

Paul

[steve_k]

Sorry to hear about the knee - nasty!

Yes, it does sound like the filters are blocked restricting fluid flow - to test the ABS on the bench you should be able to feed fluid into the Front L and R inputs and get fluid out of the respective outputs - and the same with the single rear input should pass fluid out the rear output.

I tested mine with cheap suringes connected to brake pipe stubs - you should be able to push the fluid staight through without a lot of pressure - this indicates clean -ish filters - I've had ones totally blocked.

Paul

hi paul.

thanks for the reply.

well i've spoken to my mate & he says to pull the abs system for now till he can get another pump, he wants to go for an exact copy of the set up on my car,

in the mean time i will try & test the pump & see what sort of condition its in internally.
& before anyone chimes in, he know how to drive with out abs as he's a rally driver in the modified historic class with a mk2 escort running a millington diamond 2.7 (based on an N/A cossie YB) & he knows how to pedal a car.

also about the knee, not to worry i broke it on the 9th sept 2001 at work (was at home, foot up watching the twin towers on the news) & it's been "trick" ever since, goes about 2 - 3 times a year so i'm used to it.

[steve_k]

forgot to add, there was a slight bit of fluid that did come out the abs pump but it was filthy & looked to have what looked like fine metal "shavings" in it which is what lead me to think the pump was done for.

[paultv]

I was amazed at how much rust was in the last one I opened up - it's not surprising that the solenoids seize up and the filters block solid too.

It all relates to old brake fluid full of water rotting the insides of the ABS pump unit - it shows you exactly why flushing and changing brake fluid
is so important.

Typical filthed up solenoid filter

Paul

[steve_k]

I was amazed at how much rust was in the last one I opened up - it's not surprising that the solenoids seize up and the filters block solid too.

It all relates to old brake fluid full of water rotting the insides of the ABS pump unit - it shows you exactly why flushing and changing brake fluid
is so important.



IMG_0883.JPG

Paul

i'm expecting if i open thi one up hats what its gonna look like inside. fingers crossed.

[reggid]

PS. IMPORTANT - Don't do any work on the ABS without first removing the multi pin connector for the ABS ECU - it's sensitive and can be fried with great ease.

What location is the ABS ECU and how can it be identified? maybe it is obvious

[paultv]

Its located above the glove box, you need to remove the box and upper cover trim to see it.

You only need to disconnent the cable at the pump though...you don't have to remove the ABS ECU unless you suspect its stuffed.

Paul

[reggid]

Its located above the glove box, you need to remove the box and upper cover trim to see it.

You only need to disconnent the cable at the pump though...you don't have to remove the ABS ECU unless you suspect its stuffed.



PSX_20210929_105953.jpg



Paul

ok thanks, yeah was hoping just undoing the connector was ok.

i have purchased a motive pressure bleeder so will be giving it a go soon

[paultv]

Bleeder definitely the way to go....hope you get it all sorted !

Paul