M52 swap help needed - brakes

Post Sun Apr 01, 2012 10:13 pm

My conversion is complete, the car runs and drives brilliantly, BUT the brakes are absolutely rubbish. I've bled them through 4 times now - no air in the system at all - and I've just replaced all of the discs and pads for brand new Pagid items - the brakes are still terrible. They work just about, but there is no 'bite' to them and the car takes far too long to stop.

This leads me to think it must have something to do with the servo? It's been swapped for a Clio item to allow the M52 to fit. I've read somewhere about fitting a spacer somewhere, but mine hasn't been (it came from a previously converted E30 shell so I fitted it to mine exactly as it came out of the shell). What else can I do/check to make the brakes work properly? Can anyone please offer some advice, points, measurements, whatever as I want to start driving the thing!

Thanks

Post Sun Apr 01, 2012 11:11 pm

Servo pushrod probably needs adjusting, I expect it has a long pedal?

Post Sun Apr 01, 2012 11:58 pm

Normal pedal. Feels OK after bleeding etc. no more travel than I would expect. I checked at the passenger footwell inside the car to see if the pushrod/linkage would move any further forward and it doesn't seem like there's any more travel for it. Fluid's going through the system etc. as it all bleeds properly. I'm at a loss!

Post Mon Apr 02, 2012 9:58 am

My brakes have always been a bit gash with the clio servo, I was quite careful with the spacer length and adjustment so I don't think that's it. They almost feel like they run out of vacuum before they really bite, if you keep your foot in without increasing pressure in they will eventually bite in but it takes a sec. Having driven a diesel with a knackered vacuum pump it does just feel like a kind of uneven assistance. You get used to the pressure required but it could be a lot nicer.

Post Mon Apr 02, 2012 11:24 am

blue30 wrote:My brakes have always been a bit gash with the clio servo, I was quite careful with the spacer length and adjustment so I don't think that's it. They almost feel like they run out of vacuum before they really bite, if you keep your foot in without increasing pressure in they will eventually bite in but it takes a sec. Having driven a diesel with a knackered vacuum pump it does just feel like a kind of uneven assistance. You get used to the pressure required but it could be a lot nicer.

i had this the first time i did my brakes...ended up being a master cylinder seal that had shat itself. new one on there now

Post Tue Apr 03, 2012 9:34 pm

A little more information which may lead somebody to the answer:

I read somwhere about the pipe between servo & inlet manifold should have a 1-way valve fitted to it. I've taken my pipe off and it's just a pipe, no valve. There's a 90degree plastic elbow between the servo & pipe and just a small jubille clip attaching the pipe to the manifold.

Do I need a valve? If so, what does it look like and where do I get one from please?

If I don't need a valve then I shall take the servo off at the weekend and have a look at the adjustment of the pushrod. I still don't understand where a spacer should be fitted if I need one. AGain, diagrams/photos always help!

Thanks

Post Wed Apr 04, 2012 1:30 am

you do need a one way valve sir , you can just make it out in my pic here

get yourself to a breakers yard i rekon e36 one will do the job if no e30s arrow on the valve should point to inlet correct me if im wrong someone please

Post Sun May 13, 2012 12:14 pm

Help still needed please!

I've fitted the 1-way valve which made no difference. I've also undone the master cylinder to check that the pushrod from the servo is located - it is. If I remove the m/c and look at the pushrod, how far should the pushrod be protruding? Should it be flush with the face of the servo, further in or further out?

Thanks for all help, pointers & advice.

Post Sun May 13, 2012 1:45 pm

If your using the E30 master cylinder the push rod in the servo does need to be flush or a spacer made to bring it flush

Post Sun May 13, 2012 3:25 pm

Thanks Dan. I've adjusted everything and it's better, but still not as sharp and effective as I'd like. Given that all discs and pads are brand new I'll give them some time to bed in and take it from there. Almost MOT time!