New servo and master cylinder..Danlor you have mail

[Tant]

..whew...just finished my conversion to fiesta bits....If anyone wants any tips, give me a nod.

I'd say "do it"...the brakes are so much better with much better feel and bite.

More details to follow when I manage to get my back straightened out again..that footwell is damned tight..

Cheers

Anthony

[clarenceboddiger]

What did you change, was it both master cylinder and Servo?

[Tant]

Yes mate, servo (2nd hand but cleaned/painted and almost like new now), and a new master cylinder. Ended up changing the front copper brake pipes as well as the unions on the new master cylinder were different, and I wanted to keep the old parts as a set, just in case.

It has made a huge difference. The old brakes had a solid pedal feel and very little travel, but very little braking effect, the new set up is far more progressive, with noticeably more servo, progression and "bite", but a bit more travel.

It looks a whole lot neater in the engine bay as well.

If you want the details, give me a shout

Cheers

Anthony

[greymrj]

Hi Anthony, not sure if you followed these notes
http://www.pistonheads.com/gassing/topic.asp?h=0&a...
or sorted it from scratch yourself. Is there anything that needs to be added to these notes?

[Tant]

Hello Richard
Yes I did, pretty much, although the master cylinder I have, although listed for a fiesta mk3 models you said, seems to be a slightly smaller bore. This gives a longer travel, but a higher pressure for a given effort and feels fine to me...a good degree of progression can be felt.

I found the holes in the bulkhead to be slight trial and error as I didn't use your template.

Getting the pedal box out was a swine of a job.

In the end it looks so much better...
photos to follow.

Cheers

Anthony

[greymrj]

Hi Anthony, that is all interesting. What was the part number for the master cylinder? I should be able to identify it and the bore and therefore work out the displacement. I'd also be interested to learn why you found it necessary to actually take the pedal box out rather than drill through the bulkhead, did you find a problem I didn't enviseage? There will be more owners facing this problem as old SAAB servos 'die' so the more we bottom this for them the better.

[Tant]

Hi Richard

I only had to remove the pedal box to get to the brake pedal to drill it for the bigger pin. One of those right angle drill heads would have done the trick, but I like a challenge......

The part number I have is PMF238-1258 listed for fiesta 1.1, 1.4, 1.6d, 1.8d diameter 20.64 (thought it was 21.6 before whoops)

I have some photos but I'm not sure how to post them..

Cheers

Anthony

[Tant]

edited to remove link....

Edited by Tant on Tuesday 15th July 20:09

[Barkychoc]

Ant, when you look at your photobucket picture there's 4 lines listed to paste into a forum.
Use the bottom one, and Voila!

So posting

[IMG]http://i23.photobucket.com/albums/b379/Anthony123_/newservoandMC.jpg[/IMG]

gives

[Tant]

...that's more like it...thanks Chris.

Ant

[pringli]

Sorry for late post but just back at work today, changed mine for fiesta servo - redrilled bulkhead as necessary using black paint on end of bolts to mark position of new holes and used round file where reqd to enlarge holes to get reqd position.Note: I did NOT redrill brake pedal, instead I used the plastic sleeve from the Fiesta pedal assembly and cut out the width of the brake pedal flange, I then inserted each half either side of the pedal and inserted the fiesta pin, all is held in place by the fiesta clip and cannot fail. (Dont ask for pics I cant post from work).

[greymrj]

Hi Ant, sorry for the dealy in getting back on this one. I feel a bit awkward about this. The TRW records show the PMF 238 master cylinder you fitted as 20.6mm bore against the 22.2mm diameter of the original (either the original SAAB cylinder or the later fitted Ford cylinder which is the recommended replacement). That equates to a 14% reduction in cylinder displacement, for the same stroke, which is a big difference. There are obviously good design reasons for having different sized master cylinders, and the cylinder displacement of the master has to be matched to the required displacement of the 'slave' cylinders, with a margin for safety. I have got to be honest, under no circumstances would I risk running on a master cylinder which didn't match the original displacement, I simply dont know the circumstances under which it might be crucial. You have said that you now have longer brake pedal travel, presumably approx 14% more, does anybody know whether that could be crucial in an emergency braking situation, perhaps with worn pads? Obviously it could be a serious safety issue and I would fit a PMH247.

An important issue for me when I researched this was to identify the solution that TVR used on later cars because this could be seen as an update and not a modification, and thus justifiable to insurers. It was also an issue for TRW staff as they wouldn't condone any master cylinder other than one which gave identical performance to the original.

Ironically the PMF238 you fitted is listed as old stock, no longer in production,while the PMH247 is listed as current. Incidentally the PMH247 is a black painted rather than a plated finish cylinder

The mod to the suggested approach that Ian has come up with sounds OK to me, it isnt unusual to have sleeves on such shafts/pins, all we are seeking to do is to prevent undue slack so as long as they are secure enough it does work OK and saves taking the pedal out to drill.

[Barkychoc]

Richard can you identify the master cylinder from the little plastic tag round it with a number on?
I'd like to replace it on my V8S but I'm certain with it being discs all round that it will be a different MS to the disc/drum setup. Or maybe I shouldn't worry as it was working fine when I took the car to bits!
Hey my car has wheels on now, will post a pic soon can't get it out of the garage at the moment as we've got some building stuff in front of the garage door.

Chris

[greymrj]

Hi Chris, I can certainly try from that number. I may not have the appropriate manufacturers reference book but I am sure my friendly factor will have it if I don't.
Good to hear the progress; it has been interesting (and sometimes entertaining!) following your progress!

[Tant]

Richard

ta for your reply, but I really wouldn't feel awkward if I were you. Your guide couldn't have been any more detailed, and it's my own fault if I didn't follow it. I bought my MC of e.bay, listed for the correct models, and I was aware before I fitted it that it was not the same diameter as original because the diameter was on the box. I reasoned that if the pedal travel was OK when I fitted it, the the decreased diameter would give an increased line pressure for a given pedal effort. I decided to try it and it seems to work very well indeed, with a much reduced pedal effort (probably the servo)and awsome stopping power now. I have 4 piston cosworth calipers on the front, and the pedal travel feels fine to me now.
The only doubt in my mind is that if anything bad was to happen, like an accident, that it could be seen as an unapproved modification. So I've decided to get the correct one you state and fit that...to be honest the master cyl is the easy part of the conversion. I'll let you know how I get on and give a comparison of each one.

Cheers mate

Ant

[greymrj]

Thanks Ant, I am relieved by the way you have approached that. I don't know what the 'safety margin' would be on this system and I wouldn't like any of us to find out the hard way!