pmc_3
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| posted on 12/2/05 at 04:21 PM |
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Brake problems
My car up until last weekend was running drum brakes at the front  It originally had a 1300 xflow and was then upgraded to a 2.0 pinto.
I manage to find a complete disc setup off another dutton and fitted last weekend. I ran out of daylight so didnt manage to get it bled.
The problem I have is that I tried bleeding them today. I didnt use the pressure bleeder because I couldnt get it to seal. So I went round and did
them all the old fashioned way and got a nice steady stream out of all of the bleed nipples. But there was no pressure at the pedal, you could push it
straight to the floor. So we went round and did them all again and again to make sure there was no air in the system. Still the same 
If you pump the pedal at the moment (all bleed nipples tight) it gets harder and pressurises, but as soon as you stop and press the pedal again it
goes straight to the floor.
So, the question is whats wrong? The master cylinder was fine when the drums were on, so could be calliper seals. But someone said to me that if its
pressurising the callipers seals are ok? Or is there just more air in the system?
Please help I'm thoroughly hacked off 
The brakes are all mk1 escort if that helps
[Edited on 12/2/05 by pmc_3]
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pmc_3
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| posted on 12/2/05 at 04:35 PM |
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ps I didnt mean to put it in this section lol
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britishtrident
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| posted on 12/2/05 at 04:37 PM |
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Girling systems are normally very easy to bleed --
First of all did you have your assistant the pedal held fully down to the floor while you closed the nipples ? Bleeding is a two or three man
job, the bleeding tube must be a tight fit on the nipple and the nipple should only be opened enough to allow free passage of fluid -- unscrew it too
much and air will get drawn in on the return stroke.
The pedal should be pumped slowly -- the return strokes should be very slow.
On the last stroke on each nipple the pedal should be held down while the tube is removed and the nipple tightened.
------ nothing to do with bleeding the system but did you change the master cylinder disk brakes require a different (bigger bore) mastercylinder
from the all drum setup.
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Dick Axtell
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| posted on 12/2/05 at 04:43 PM |
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Hi PMC,
Q: Did you change the master cyl?
Remember the calipers have larger pistons, and require larger displacement.
Mcyl for your drum/drum setup may not have enough volume in the secondary (i.e. front) chamber (assuming you fitted the OE dual circuit tandem type
mcyl).
Q2: What bore size is your existing mcyl?
Q3: Did you follow the appropriate bleeding sequence? For disc/drum, start with the nearside front caliper (longest front pipe run), then the osf,
followed by the longest rear pipe run (nsr wheel cyl), and finally the osr w/cyl.
Work-in-Progress: Changed to Zetec + T9. Still trying!!
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pmc_3
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| posted on 12/2/05 at 04:54 PM |
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Yeah we did the bleed nipples up with the pedal full depressed and did slow strokes.
How can I find out the bore of the master cylinder? I used the original, was told it should be ok.
[Edited on 12/2/05 by pmc_3]
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Dick Axtell
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| posted on 12/2/05 at 04:57 PM |
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So it's the Escort Mk 1 OE mcyl?
Work-in-Progress: Changed to Zetec + T9. Still trying!!
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pmc_3
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| posted on 12/2/05 at 05:05 PM |
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I presume so, its connected to a mk1 pedal box as well. I can get a you a pic if it helps
[Edited on 12/2/05 by pmc_3]
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pmc_3
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| posted on 12/2/05 at 05:22 PM |
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Right I went and had a look, its a Girling master cylinder
and these are the callipers
They use 219mm discs
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rusty nuts
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| posted on 12/2/05 at 05:39 PM |
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Bore size may be on side of master cylinder? When using a pressure bleeder professional type or Easibleed don't use more than about 15-18 P.S.I
. Using higher pressure will cause leak from connector. Doesn't seem to make much difference what order brakes are bled when using pressure
bleeders. May be worth clamping front hoses and trying pedal, if pedal is a lot firmer it's either air in system or master cylinder bore is too
small.
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pmc_3
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| posted on 12/2/05 at 05:46 PM |
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I tried clamping the osf flexi hose earlier and the pedal went firm. I then tried putting it on the nsf one and when I tried the pedal it went to the
floor. So I presumed a problem with the osf but when I tried it again with that flexi hose clamped it went to the floor?
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rusty nuts
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| posted on 12/2/05 at 06:07 PM |
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May possibly be collapsed master cylinder? Have had master cylinders fail when trying to bleed brakes due to using more piston travel than when brakes
are applied. If in doubt change it for the correct one for disc brakes .
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britishtrident
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| posted on 12/2/05 at 06:21 PM |
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quote:
Originally posted by rusty nuts
May possibly be collapsed master cylinder? Have had master cylinders fail when trying to bleed brakes due to using more piston travel than when brakes
are applied. If in doubt change it for the correct one for disc brakes .
Dosen't usually happen with Girling -- seen it many time with high mileage Lockheed systems the connical spring breaks and with Teves
master cylinders the rubber seal can reverse (goes without saying I don't like Teves systems).
I think the master cylinder bore on a Mk1 Escort with disks but no servo was 0.75" with a servo it would be 0.8" or more.
With drums it would be 0.625" or 0.7"
[Edited on 12/2/05 by britishtrident]
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pmc_3
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| posted on 12/2/05 at 06:21 PM |
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I think we may have found the problem. Just been chatting to a friend and it appears I may have fitted the callipers on the wrong sides, it made sense
to me to have the bleed nipples at the bottom but it appears i'm wrong!
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Hellfire
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| posted on 12/2/05 at 07:28 PM |
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quote:
Originally posted by pmc_3
I think we may have found the problem. Just been chatting to a friend and it appears I may have fitted the callipers on the wrong sides, it made sense
to me to have the bleed nipples at the bottom but it appears i'm wrong!
AFAIK calliper orientation shouldn't matter... better if nipple upright for obvious reasons. Our rears are nipple down and have bled pretty
easily when orientated to the upright position for bleeding.
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rusty nuts
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| posted on 12/2/05 at 08:52 PM |
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With an intermittant firm pedal with brake hoses clamped I would still suspect a faulty master cylinder, but as British Trident has already suggested
master cylinder bore is probably different for drums and discs. Wouldn't recommend using what could very well be a suspect 20 year old master
cylinder . O.K. on a clutch perhaps but not brakes.. also easy enough to fit calipers with bleed nipples at top to help bleeding.
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pmc_3
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| posted on 12/2/05 at 11:04 PM |
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Well i'm gonna swap the calipers over in the morning and see what happens, worth a go. My mate said he was having real problems bleeding the
brakes on his sierra xr4x4 and it was because there were two nearside calipers fitted at the front. I'll check the markings on the master
cylinder and see what bore it is too.
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britishtrident
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| posted on 13/2/05 at 09:24 AM |
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quote:
Originally posted by Hellfire
quote:
Originally posted by pmc_3
I think we may have found the problem. Just been chatting to a friend and it appears I may have fitted the callipers on the wrong sides, it made sense
to me to have the bleed nipples at the bottom but it appears i'm wrong!
AFAIK calliper orientation shouldn't matter... better if nipple upright for obvious reasons. Our rears are nipple down and have bled pretty
easily when orientated to the upright position for bleeding.
Its less of a problem a problem if the pads are new and pistons pushed right back but if the pads are even slightly worn air will be trapped in the
bore. A good get you out of jail free card with difficult to bleed system is to pump the pistons out a little then push them fully home -- this
will often get rid of difficult air locks.
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andybod
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| posted on 13/2/05 at 09:27 AM |
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turn the calipers round so the bleed nipple's are at the top air can get trapped in them if turned upside down i did have this problem a while
back got a call from a friend who couldn,t bleed his brakes he'd fitted the calipers incorrectly bleed nipples at bottom turned them round and
they bled fine
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britishtrident
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| posted on 13/2/05 at 09:28 AM |
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The master cylinder looks like it came from a car with a servo --- which would indicate it is a disk brake type.
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pmc_3
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| posted on 13/2/05 at 12:13 PM |
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Turned the calipers round this morning and bled the system, fixed!  I now have a rock solid pedal and brakes 
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