Sportster Brake Master Cylinder

Nigbo · #1 31st May 2022, 08:58

My Ford Sierra master brake cylinder is leaking ( fitted to dual brake booster) , struggling to find a replacement, everywhere is out of stock for Cifam ( 202-099) or Metelli ( 05-099) , its the 22mm bore , TRW have equivalent PMH173 but at cost of 260, of course has to fit adaptor plate, did anybody use a different type that fits the adaptor plate and the tight space available

AlanHogg · #2 31st May 2022, 16:12

I will check out the garage as I think I may have a Sierra one on the shelf of spares. Will post back on here.

AlanHogg · #3 1st June 2022, 06:42

Apologies, as I seem to have let it go with other spares when I sold the Cabrio.

peterux · #4 1st June 2022, 07:48

Bigg Red are listing m/c repair kits but probably best to check with them the correct part number for yours.

peterux · #5 5th June 2022, 08:43

Kit spares are still listing them....
https://kitspares.co.uk/products/brake-master-cylinder

Nigbo · #6 5th June 2022, 21:54

Kit Spares list the bore size as 10mm but the original most folk fitted for the dual booster was 22 mm , that's a big difference

MartinClan · #7 6th June 2022, 08:42

10mm is a very strange bore size for a master cylinder. Could just be a mistake in the listing. It looks very similar to the one I used.

New servo by Robin Martin, on Flickr

Could be worth checking with them....

Cheers, Robin

Mike · #8 7th June 2022, 21:07

Hi Nigel

This is interesting as my Sierra Brake Master Cylinder bought at the same time as yours has also failed.
And like you I searched far and wide to find a direct replacement without success.
I have bought a repair kit containing several seals and hope this solves the problem.

Interestingly Peter Edwards managed to find a replacement being offered on eBay -
https://www.ebay.co.uk/itm/334299608631

Nigbo · #9 8th June 2022, 08:13

Mike
yes I had discovered that one , was a bit wary because the photo did not look too much like the original Cifam model, but maybe its just a generic photo . Anyway I don't fancy the master cylinder rebuild route and have taken the plunge and brought the ebay. I will let you know how I get on. It's concerning the otherwise across the board unavailability.
I am concerned about the failure, it was leaking brake fluid back into the booster, hope its not going cause any issues with the booster.

Nigel

Grey V8 Pete · #10 8th June 2022, 20:45

I will be interested to hear your feedback. It’s a job that’s on my preventative maintenance list too and I also found the OE 22mm bore master cylinders are out of stock everywhere. I suspect that for those alternative parts the brake pipes may need re routing as the side bosses could be facing the outside of the car. Not a major problem, just a bit of extra work. Also worth checking that the bolt holes in the mounting flange are the same pitch or you will need to modify something there. Finally worth checking that the depth of the rear piston hole ( relative to the flange face) is the same as your existing one, to ensure that the servo plunger has the correct clearance to work correctly. Peter.

Mitchelkitman · #11 9th June 2022, 08:10

I suspect the new Sierra master cylinders from kit parts (featured above) are likely to have m10 connectors for the pipes, and it's worth checking with kit spares to ascertain the bore size.
It's worth looking for alternatives which are readily available - with a bit of research I was able to replace an escort mk2 servo (on a Rickman Ranger) with an alternative used on LR Defender. Minor changes I made to the Escort pushrod meant the job took just an afternoon. Cost of servo was 63 pounds 4 years ago. OEM manufacturers won't change parts when they sell them to different manufacturers unless it's absolutely necessary (cost) so the only change may be a part number!

Grey V8 Pete · #12 11th June 2022, 07:45

Any chance of a photo of your new one, next to the existing if possible. Not sure about the choice of metal if it really is an aluminium alloy?

Grey V8 Pete · #13 13th June 2022, 08:52

A quick check with a magnet will show if your new master cylinder is dural or steel. That said the wheel cylinders on my drum / drum braked Classic are steel on the front and dural on the rear.

Grey V8 Pete · #14 19th June 2022, 07:30

Hi Mike.
Yes I have now bought the same, for the same reason. With the dual servo fitted the master cylinder is further forward so the front unused boss will foul the bonnet. If it is completely solid it could probably be machined off?
Regards. Peter.

Mike · #15 20th June 2022, 05:19

Hi Peter
I have offered my MBC up to the old one and am certain mine will not foul.
You could fit a thin spacer between the servo and firewall on the two offside mountings, angling the MBC towards your engine to prevent fouling the bonnet side.

Grey V8 Pete · #16 20th June 2022, 08:55

Quote:

Originally Posted by Mike

Hi Peter
I have offered my MBC up to the old one and am certain mine will not foul.
You could fit a thin spacer between the servo and firewall on the two offside mountings, angling the MBC towards your engine to prevent fouling the bonnet side.

Hi Mike. Yes I had considered that but I don’t like the misalignment that causes, even if a ball joint clevis is used. If you put a wire down the opposite port it only goes half way across the cylinder so I am pretty sure the redundant outer boss is solid. If it could be Xrayed it would confirm that immediately! Peter.

Mike · #17 21st June 2022, 22:39

Hi Peter
Later chassis - like mine - had the face of the pedal box angled to achieve this from the factory - hence why I don’t have a problem.
You will be fine with a couple of spacers particularly if you have a rose joint to accommodate the minor angle change.

PS
What is the matter with this site? It only accepts one line of text on the original post!

Grey V8 Pete · #18 20th October 2022, 20:10

[QUOTE=Mike;107787]
Hi Mike. After a summer concentrating on my classic I have now returned to the Marlin Hunter master cylinder maintenance. After a flash of inspiration I removed the separate bonnet side and with the bonnet top closed I looked at the space around the existing master cylinder. My dual servo is also tilted inwards with packing and there appears to be enough clearance for the redundant boss on the generic master cylinder! Phew! So currently installing the new one. Peter.

peterux · #19 12th December 2022, 12:10

Hi Peter,
Did you have an issue with this master cylinder?
Cheers, Peter

Grey V8 Pete · #20 13th December 2022, 17:34

Quote:

Originally Posted by peterux

Hi Peter,
Did you have an issue with this master cylinder?
Cheers, Peter

Hi Peter.
I did cut a small amount off the redundant front solid boss to ensure adequate clearance with the bonnet. If I can attach two photos they show the cut line which is the inner blue line in each case. That said, as my bulkhead is flat where the servo is mounted, I had already used packing washers to mount the new dual servo to get clearance. Peter.