Brake master cylinder, right hand drive.
- Thread starter sdoyle
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The parts books don’t show a unique master for RHD. Early cars were 23.8mm and later cars were 22.2mm.
Wladek
Well-Known Member
As far as i know - RHD & LHD are different.
Repair kits available at W&N prove it
https://www.wallothnesch.com/en/bremse/bmw-2-5-cs-3-0-csl-e9/katalogbild-34-15.html
Repair kits available at W&N prove it
https://www.wallothnesch.com/en/bremse/bmw-2-5-cs-3-0-csl-e9/katalogbild-34-15.html
Simufly
Well-Known Member
Yes they are different. RHD has two remote servos.
RHD 34311102812
LHD 34311103742 plus two others depending on bore diameter.
RHD 34311102812
LHD 34311103742 plus two others depending on bore diameter.
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sdoyle
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Thank you all for the help. For the record, the LHD has 5 pipes, the RHD has 2 pipes, they totally different. Again many thanks for the help. Sean.
The problem I have is that I not been able to get the brakes working properly, there is very little braking on the front wheels, but very good on the back, if I press the brake hard, the rear wheels will drag / slide.
All wheel cylinders have been refurbished, front and rear. I have replaced the two remote in-line servo units, with no change. I have adjusted the rear mounted pressure valve.
The master is new. Any sussestions, please. Thank you.
Sean.
The problem I have is that I not been able to get the brakes working properly, there is very little braking on the front wheels, but very good on the back, if I press the brake hard, the rear wheels will drag / slide.
All wheel cylinders have been refurbished, front and rear. I have replaced the two remote in-line servo units, with no change. I have adjusted the rear mounted pressure valve.
The master is new. Any sussestions, please. Thank you.
Sean.
Simufly
Well-Known Member
Ok might sound silly but has the piping been changed? Are you 100% certain the pipes all go to their correct destination. Are all the flexi pipes new? They can appear fine on the outside, but still be blocked internally.
Is the rear pressure limiter workin correctly? Adjusting it is not a good idea, unless you access to dual hydraulic pressure gauges.
Have you bled the brakes in the correct order (This is VITAL on RHD cars)
Have you got a firm pedal?
Where are you located?
Is the rear pressure limiter workin correctly? Adjusting it is not a good idea, unless you access to dual hydraulic pressure gauges.
Have you bled the brakes in the correct order (This is VITAL on RHD cars)
Have you got a firm pedal?
Where are you located?
Wladek
Well-Known Member
The problem also might be in pressure regulator.
Most of them much or less are rusted inside & valve might not moving properly.
Most of them much or less are rusted inside & valve might not moving properly.
sdoyle
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Ok might sound silly but has the piping been changed? Are you 100% certain the pipes all go to their correct destination. Are all the flexi pipes new? They can appear fine on the outside, but still be blocked internally. Àll the pipes are new including the flexibles. I am am sure the pipe destinations are correct.
Is the rear pressure limiter workin correctly? Adjusting it is not a good idea, unless you access to dual hydraulic pressure gauges. I know it's not a good idea to ajust the pressure valve, but had to try something. I also replaced it with a bias control valve fro a competion car, no change, I have just got a pair of pressure gauge, but have not used them yet.
Have you bled the brakes in the correct order (This is VITAL on RHD cars). Adjusted as per a BMW workshop maual.
Have you got a firm pedal? Pedal feeds perfect.
Where are you located? Ireland.
The pressure is not rusted internally.
Is the rear pressure limiter workin correctly? Adjusting it is not a good idea, unless you access to dual hydraulic pressure gauges. I know it's not a good idea to ajust the pressure valve, but had to try something. I also replaced it with a bias control valve fro a competion car, no change, I have just got a pair of pressure gauge, but have not used them yet.
Have you bled the brakes in the correct order (This is VITAL on RHD cars). Adjusted as per a BMW workshop maual.
Have you got a firm pedal? Pedal feeds perfect.
Where are you located? Ireland.
The pressure is not rusted internally.
Simufly
Well-Known Member
Ok put you pressure gauges on the front caliper bleed nipples. Check for identical (ideally) or very near pressures from circuits 1and 2 .repeat for the other side. Are the pressure the same from both circuits on both calipers?
If yes the pistons in the calipers are frozen!
If yes the pistons in the calipers are frozen!
I spent allot of time with my RHD brakes, rebuilt the master, the servos and the calipers. Also replaced most pipes and all hoses. Then spent some time bleeding them, which is fun on RHD.
I suspect that it is air in the system, those servos are really difficult to bleed. I did the entire car from front to rear, then the servos, then did it all again. Then tested it. Then drove it and did it all again. It was much harder to get all the air out when I changed many pipes rather than just the hoses. Do you have a pressure bleeder? I have one that runs from the spare tyre pressure, I link it to my mountain bike tyre and try it with increasing pressure until it works.
If you want to talk it over send me a pm and we can have a telecom. I am no professional, but am willing to try to help.
CB
I suspect that it is air in the system, those servos are really difficult to bleed. I did the entire car from front to rear, then the servos, then did it all again. Then tested it. Then drove it and did it all again. It was much harder to get all the air out when I changed many pipes rather than just the hoses. Do you have a pressure bleeder? I have one that runs from the spare tyre pressure, I link it to my mountain bike tyre and try it with increasing pressure until it works.
If you want to talk it over send me a pm and we can have a telecom. I am no professional, but am willing to try to help.
CB
I was just talking to an e9 specialist last week and he said what a pig it is to get the RHD brakes working well. He stressed that correctly bleeding them is the most challenging step and usually may need 4-5 goes before they work properly.
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Simufly
Well-Known Member
A Gunson pressure bleeder is very useful, but dont do what I did, during bleeding the system I omitted to keep the reservoir topped up. Big Doh!
Eventually got all the air out, (I think!)
Nice firm pedal and good brakes anyway.
Eventually got all the air out, (I think!)
Nice firm pedal and good brakes anyway.
My $0.02, have you bled the master at the pipe connections? Apparently that has to be done once the calipers and lines are done.
sdoyle
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Firstly many thanks for the various answers / suggestions. Apologies for not responding sooner, I have been away, a poor excuse, I know.
It seems from all the comments that I need to bleed the system more carefully, so I will do that, I will report back then.
Again many thanks for the help much appreciated .
Sean.
It seems from all the comments that I need to bleed the system more carefully, so I will do that, I will report back then.
Again many thanks for the help much appreciated .
Sean.
daddywad
Well-Known Member
Hi all, John Castle from the UK E9 Register has written a paper on the brakes which may help all.
Attached.
Mark
Attached.
Mark
What I've done with tricky to bleed systems is to cycle through brake fluid several times over (not mucky stuff obviously) until you've got the air out. And then flush this recycled fluid out with fresh
Saves wasting loads of fluid
Saves wasting loads of fluid
sdoyle
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Thank you, very useful document.
sdoyle
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Good idea, many thanks.
jvrenaudon
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Might I suggest caution when dealing with these servos. They might look alike but they are not. Last year I took delivery of some stuff taken from a stripped-out RHD e9 and , amongst all the stuff, were two servos. On inspection, one carried the Ate reference number 29/33 and is identical to the servos fitted on my 1973 CSL and my 1974 CSI (14mm bore} but one of the others is reference Ate 29/10 (16mm bore). Fortunately, the other servo I acquired is a 29/33 and I am assuming that the 29/10 is possibly from a 2002 at some stage. I am reasonably certain that the two mis-matched servos ended up fitted in the same car before I got hold of them. Best, John