brake problems i give up now!!!

[steve_k]

Well it looks like I won't be doing anymore for a day or two seeing as my back has decided its had enough & thrown itself out,

Fingers crossed I'll be back out there by Tuesday.

[martauto]

Well it looks like I won't be doing anymore for a day or two seeing as my back has decided its had enough & thrown itself out,

Fingers crossed I'll be back out there by Tuesday.

Mart.

[steve_k]

well i managed to get outside to the car today,

changed the rubber grommet on the servo, old one just fell out.

fitted the new one, put the check valve in (took some pushing in), made sure all the unions were good & tight,

then moment of truth, started the engine with my foot on the brake pedal, when the engine started the pedal went down a little, so i pressed the pedal a few times & it felt a lot lot better,

pumped the pedal a few times & it get pretty firm, went about half way down & wouldn't go any further.
i've not had chance to move the car back or forth on the drive yet as i'm having a couple of new tyres fitted to the daily, so i'll hopefully be trying it tomorrow or later today (depending on how my back feels lol).

but safe to say the brakes feel a lot better than they did before,

soon as i get a chance to try it on the drive i'll report back.

fingers crossed.

[steve_k]

also i moved the car as far backwards & forwards as i could & each time i pressed the pedal the car jolted to a alt & the pedal was pretty firm, but only a proper(ish) tomorrow will tell.

[flybynite]

also i moved the car as far backwards & forwards as i could & each time i pressed the pedal the car jolted to a alt & the pedal was pretty firm, but only a proper(ish) tomorrow will tell.

Sounds promising, good luck with it

[steve_k]

also i moved the car as far backwards & forwards as i could & each time i pressed the pedal the car jolted to a alt & the pedal was pretty firm, but only a proper(ish) tomorrow will tell.

Sounds promising, good luck with it

Thanks buddy, I'll post up what happens.

[martauto]

Were are hanging in suspenders here Steve
Sounds cool .

Mart.

[steve_k]

Were are hanging in suspenders here Steve
Sounds cool .

Mart.

That image don't bare thinking about .

Soon as I know I'll post up, & just keeping my fingers crossed.

[steve_k]

well i've been out to the car this morning & tried the brakes again.

i moved the car back & forth along the drive (5 car lengths each way) & at first the brakes worked fine (plenty of bite & decent pedal travel & effort) but after the 4th time the pedal started to go soft again.

i'm leaning towards either the servo or the non return valve being faulty as it seems to be losing vacuum after a couple of times using the brakes. also i'm starting to suspect the rubber grommet i used could be faulty as it's off the original servo that i took off the car,

after i turned the engine off & press the pedal a couple of times the pedal goes rock hard & if i restart the engine with my foot on the pedal it drops slightly.

i even opened a bleed nipple with the pedal held down (length of wood wedged against the seat) & there was fluid coming out, i closed it & checked all the unions & they were dry.

i've found this online

https://i267.photobucket.com/albums/ii3 ... 9241490006

& soon as it's stops raining i'll be back outside trying it.

i'm starting to lose hope with this car as it's really the only thing stopping it from being back on the road despite the fact i've rebuilt the engine (high spec stroker build), gearbox, chassis & bodywork yet this one little bit has stopped me dead in my tracks.

i'll have a look through the bently manual see if that shows anything i could try.

[steve_k]

well i've been out & tried the tests in that link & from what i can gather the both the servo & M/C are working as they should.

i'm so so confused right now.
my dad is coming round tomorrow (providing it don't rain) & i'll get him to help me bleed the brakes again just in case there's air still in the system (can't hurt to try).

i really really want to get this sorted as there's 2 local shows i want to take it to next month.

[steve_k]

well the saga continues with a new problem/symptom.

just been out to try the brakes again, moved the daily out the way, got in the sport, pressed the brake pedal a few times to deplete any vacuum in the servo, started the engine with the pedal held down, & the pedal went down a little,

i let the engine idle for a few minuets whilst i checked for any leaks & then backed the car up to the end of the drive & tried the brakes, they worked fine, moved it forward & when i tried te brakes the pedal went soft & i had to pump the pedal of a couple of times to get the car to stop,

now the new symptom is this.

when i moved the car forward & stopped i left the engine idling & pumped the brake pedal a few times & i noticed when i did that the engine would hunt up & down which makes me think there's a vacuum leak somewhere.

well i checked round the engine with carb cleaner for any leaks & i couldn't find any.
also i noticed that when i press the brake pedal there's the sound of escaping air/hissing at the back of the servo behind the glove box.

this is making me think even more that the servo is bust/on it's way out.

i really am at the end of my tether with this car now & so close to getting rid.

[flybynite]

OK my guess of an intermittent vacuum leak still stands, but if it is not around the pipework then from what you say I am thinking a vacuum leak in the servo that only happens at a certain point in pressing the brake. Is it the E90 servo ?

[steve_k]

OK my guess of an intermittent vacuum leak still stands, but if it is not around the pipework then from what you say I am thinking a vacuum leak in the servo that only happens at a certain point in pressing the brake. Is it the E90 servo ?

yes it is the e90 servo,

i'm leaning towards the diaphragm having a small hole that like you say opens at a certain point.

got another one on the way (cheap enough on ebay) to try & i'll make sure the O ring between the M/C & servo is there as mine appears to have gone walk about.

[steve_k]

also the hissing sound when i press the pedal is making me thing the diaphragm might have gone same as it did on the original e30 one.

[steve_k]

Well mu replacement servo has turned up today,

Checked it over as best I could (stood it on the clevis fork & pushed down on it) & couldn't hear any air escaping (hissing sound) so hopefully I'll get chance to fit it & test the brakes either tomorrow or Wednesday,

Also it gives me a spare M/C as well which will get a rebuild & be kept as a spare.

So, fingers crossed

[martauto]

Fingers are hurting Steve, hope this works mate .

Mart.

[steve_k]

Fingers are hurting Steve, hope this works mate .

Mart.

So are mine, I think they've locked

I'm going to make a start on it soon,

[steve_k]

well thats the old servo out & the new/replacement one in,

Also I readjusted the pedalback to where it should be so everything lined up as it should,


i'll be testing it in the morning when the battery is charged & if I get a chance I'll te bleed the brakes to make sure there's zero air in the system.

[steve_k]

well a little update,

replacement servo works spots on, but before i tested the brakes i had a check round the M/C & reservoir & noticed a tiny tiny amount of brake fluid around the tops of the rubber grommets on the M/C.

now bare in mind i'm using a remote mount fluid reservoir (from a 2002 Tii & the 45degree inlet elbows) & the fluid was around the inlet elbows, had a look & it would appear that the grommets are past their best, so new ones on the way,

so, to make sure i wasnt imagining it i got my dad to press te pedal a few times while i kept an eye on the M/C to see if it was leaking on top.

low & behold as he pressed the pedal i could see that the pressure was causing the elbows to lift slightly & a little fluid was seeping out.

so, new grommets & elbows on order, soon as they get here they will be replaced & the brakes bled with the power bleeder,

watch this space ;)

[martauto]

Watching in anticipation mate

Mart.

[steve_k]

Watching in anticipation mate

Mart.

So am I mart,

Soon as the bits get here & I get a dry day ill be all over it.

[martauto]

Watching in anticipation mate

Mart.

So am I mart,

Soon as the bits get here & I get a dry day ill be all over it.

Mart.

[steve_k]

Well the parts I needed arrived, got them fitted tonight & bled the brakes on my own using a vizibleed one man bleeder,

While inwas bleeding the brakes I noticed that the front drivers side braided line had a kink/twist in it right near the caliper.

Now to my mind that wouldn't be helping at all, so I straightened it out as best I could & rebled that caliper.

I went to try the car but the battery was flat so soon as I get chance I'll be trying them again & hopefully they work properly.

This has held me up for so long it's unreal.

[martauto]

Fingers are still crossed and hurting like hell !!!

Mart.

[steve_k]

time for a small but (slightly) important update.

now, bare in mind i'm using a remote mount fluid reservoir & i've been reading on various other forums (honda, nissan, drifting etc) that some folk who had also used a remote reservoir that they had also had problems with a spongy brake pedal, & that by going back to one that was on top of the M/C the problem had been sorted.

so, into the black hole i call a shed, dug out the one that came with the new M/C, fitted that & went to bleed the system (again), i bled it using a vizibleed one man bleeder (pipe with a one way valve on the end), still a bit of air in the system so decided to use my gunson ezibleed,

one big problem, i couldn't find it anywhere so, seeing as it is saturday i rang the local motor factors, "oh yess we carry them, can be here monday & will be £35" no chance, tried ECP, non in stock, so i tried halfords, thankfully they had some in, so off i went to mansfield.

got back to mine & filled it with some royal purple 5.1 fluid i had so i could see when the new stuff was coming through, bled it up till the new fluid was coming through with no air in the system,

tried the pedal a few times & it was getting a little harder to press with the engine off as it should do.

got to wait till monday before i can drop it down & move it back & forth on the drive as it turns out the battery was knackered, so the new battery will be here on monday so while i'm waiting for that i'll bleed the system again (can't hurt can it?) & then it's D day.

[steve_k]

Well I tried the brakes again this morning.

Still the same,

So far I've replaced the e90 servo for a known good one (off a very low milage car) swapped the M/C for a brand new one, bled the system 3 times with a gunson ezibleed but its still the same.

But what I can't understand is that with the engine off the pedal is rock solid & only drops a few mm when I start the engine with the pedal pressed,

I did notice that the passenger side front wheel was slightly stiff to rotate after I bled the system which makes me wonder if the caliper is sticking,

Does this sound plausible to anyone?

I'm getting to the end of my tether with this now as it's really holding me up.

[steve_k]

Also, I noticed a patches of what would appear to be brake fluid on the ground where I tried the brakes each time which says to me that the banjo bolt could be faulty.

[steve_k]

Well after a bit of investigation it looks like the banjo bolt on thr caliper could have failed as there was a small amount of brake fluid where the braided line goes into the banjo, new one on order so just got to wait till it arrives then try again,

Still don't explain what's going on though properly.

[flybynite]

Well with all that you have done you need to go back to basics. Some things will free up and seat with use but if you can't get it on the road then that is not an option. Fluid could be getting past the caliper piston seal or it could be the banjo but I would probably bet on the former. Dry seals etc.

What pressure are you using on the ez bleed? Quite easy to over pressure some seals that are not normally under pressure if the tyre is too full. I use the hand-pump ones or the vacuum type for that reason.

Could be a blown seal, holds with no assistance but vacuum assistance is enough to push past.

I would check each caliper and move back from there. Do the pistons move out and return properly? Wheel spin freely then stop with a small press of unassisted brake, then spin again?

[steve_k]

Well with all that you have done you need to go back to basics. Some things will free up and seat with use but if you can't get it on the road then that is not an option. Fluid could be getting past the caliper piston seal or it could be the banjo but I would probably bet on the former. Dry seals etc.

What pressure are you using on the ez bleed? Quite easy to over pressure some seals that are not normally under pressure if the tyre is too full. I use the hand-pump ones or the vacuum type for that reason.

Could be a blown seal, holds with no assistance but vacuum assistance is enough to push past.

I would check each caliper and move back from there. Do the pistons move out and return properly? Wheel spin freely then stop with a small press of unassisted brake, then spin again?

I'm going right back to the start,

I'm using the ezibleed at about 15psi as I know they can be a bit hit & miss,

As for the seal? They were replaces early last year, but while I was there I decided to check the pistons on the passenger side,

I removed the caliper & pushed the pistons back in, refitted it back over the disc & pumped the pedal a few times & checked the caliper.

All the seals I could see were dry, yet there was a slight bit of fluid were I found it earlier but I did notice that the outer side pistons did not move out, looks like they are sticking,

So either later today or tomorrow I'll strip that caliper down, re grease the pistons & refit the caliper & try again.

But while the caliper is apart I'll blow some compressed air through it to make sure there's no blockage.

& ill replace that banjo when it turns up.

I really do hope this sorts it out once & for all.

[e30kombikat]

I also need to shorten the brake opwrating pushrod can anyone assist whether (when facing towards the bu;khead) I turn clockwise oranti-clockwise to shorten it?
Thanks,
Gordon

[steve_k]

Well time for another update,

Took the passenger side caliper off, took the pads out (one was jammed on one end, there's a slight hint),

I placed a block of wood in the middle & forced the pistons out with compressed air,

Stripped the caliper down & cleaned up the pistons, fitted new seals & dust boots,

Rebuilt the caliper & refitted the pads (had to knock one back in, another hint).

Block of wood in between & used the airline again,

Only 3 piston came out as one was still in behind the end of the pad that had to be knocked in.

Took the pads out & dug out the old pads & put those in,

Airline & block of wood again, & surprised surprised all 4 pistons came out.

I compared the new pads to the old ones & one of the new pads was about 1.5 - 2mm longer than the rest.

Looks like a manufacturing error,

I've not long got off the phone with the supplier who after I explained what had gone off & what I had found d accepted full responsibility & has issued a full refund (ferrodo ds3000 pads ain't cheap) & is sending me a full replacement set that should be here by Saturday,

So, let's see if these new ones fit first time.
If it turns out that that was the problem all along I'm gonna scream lol.

Only time will tell.

[steve_k]

Well the new pads arrived late yesterday & I fitted them this morning, bled the system 3 times till I got a firm pedal & tried them again.

Still the same!!!

So far I've replaced the servo for a known good one, a brand new M/C (bench bled before fitting) & resivour, Rebuilt all for calipers (new pistons & seal all round), new pads on the front, replaced a leaky banjo on the front,

Pumped about 3.5L of brake fluid through the system & yesterday I'm still having the same problem.

I really am at a loss as to what could be causing it,

Surely someone must have been through this before? I really don't know what to try or do with it now.

[stones]

Could it be one of your lines is bulging? You posted this awhile back.

Well the parts I needed arrived, got them fitted tonight & bled the brakes on my own using a vizibleed one man bleeder,

While inwas bleeding the brakes I noticed that the front drivers side braided line had a kink/twist in it right near the caliper.

Now to my mind that wouldn't be helping at all, so I straightened it out as best I could & rebled that caliper.

I went to try the car but the battery was flat so soon as I get chance I'll be trying them again & hopefully they work properly.

This has held me up for so long it's unreal.

You could test this with a bit of hard line to rule it in or out.
HTH

[steve_k]

Could it be one of your lines is bulging? You posted this awhile back.

Well the parts I needed arrived, got them fitted tonight & bled the brakes on my own using a vizibleed one man bleeder,

While inwas bleeding the brakes I noticed that the front drivers side braided line had a kink/twist in it right near the caliper.

Now to my mind that wouldn't be helping at all, so I straightened it out as best I could & rebled that caliper.

I went to try the car but the battery was flat so soon as I get chance I'll be trying them again & hopefully they work properly.

This has held me up for so long it's unreal.

You could test this with a bit of hard line to rule it in or out.
HTH

i'll check it out when i've calmed down, can't hurt to try.