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Can anyone ID this master cylinder (PICS)
GregSL75 - 17/8/08 at 01:35 PM

See attached photies, it runs the brakes on my Autograss car, looks like a bit like a Lucas Girling Landrover Series 3 clutch master, but the reservoir is cranked back rather than upright, all the pics of replacement S3 items (paddock spares etc.) have upright reservoirs.

It's a Girling cylinder, P/N is 310340A but that doesn't turn anything up on google....

Also the rod linkage is different, probably a replacement item, but may provide a clue. It has a clevis rather than a threaded end.

TIA!

GregSL75 - 17/8/08 at 01:37 PM

attachment

GregSL75 - 17/8/08 at 01:38 PM

saddle / clevis rod..

Mr Whippy - 17/8/08 at 02:02 PM

Triumph Spitfire/GT6

http://www.spitbitz.co.uk/html/used_parts.html

http://www.powertrackbrakes.co.uk/products.html





[Edited on 17/8/08 by Mr Whippy]

GregSL75 - 17/8/08 at 04:29 PM

Looks pretty close, i'll do a bit of digging, cheers for the tip off..!

britishtrident - 17/8/08 at 04:59 PM

With Girling single circuit cylinders fitting a new repair kit is successfull 99% of the time.
To find the right seal kit all you need is the bore size, the resevoir design dosen't matter as the internal parts for a given bore size are all the same.

The bore size will either be cast into the side of the cylnder body or you can measure the piston directly.

What you need to measure is the bore of the cylinder, common Girling sizes are
5/8" = 0.625" Repair kit # SP1963
7/10" = 0.7" Repair kit # SP2102
3/4" = 0.75" Repair kit # SP1967

Your local motor factor or LSUK branch should have them failing that Brakes International on the web or any old car part specialist, or even Merlin Motor sport.

When fitting polish any crud or corrosion out the pedal end of the cylinder and grease the end of the bore well with Girling Red Rubber grease


[Edited on 17/8/08 by britishtrident]

GregSL75 - 17/8/08 at 07:00 PM

The symptoms are just lost efficiency, it hasn't totally failed, it's just that it's very hard to lock the brakes now and the pedal feels a bit spongier, not really bad, it engages almost straight away it just feels like there is air in the system and I have bled it manually about 3 times and pressure bled it twice, so I am starting to suspect a M/C on it's way out, does that sound like symptoms of a partially failed seal in the cylinder??

Mr Whippy - 17/8/08 at 08:37 PM

Not really tbh, sounds more like the hoses are collapsing inside, how old are they? When the seals go on the m/c they especially on single ones you will see plenty of fluid leaking out from behind the dust cover. I’d take off the hoses and try blowing through them, don’t suck unless you like going to hospitals. If there collapsing then you’ll struggle if at all to blow through them. Oh yeah and try tying them in a knot too, they should still be open.

[Edited on 17/8/08 by Mr Whippy]

britishtrident - 18/8/08 at 08:58 AM

quote:
Originally posted by GregSL75
The symptoms are just lost efficiency, it hasn't totally failed, it's just that it's very hard to lock the brakes now and the pedal feels a bit spongier, not really bad, it engages almost straight away it just feels like there is air in the system and I have bled it manually about 3 times and pressure bled it twice, so I am starting to suspect a M/C on it's way out, does that sound like symptoms of a partially failed seal in the cylinder??



Depends on the style of caliper but you have described the classic symptoms of a seized piston (or pad) in one of the calipers, the spongeyness you describe is one of the caliper brackets flexing under pressure and springing back. This really only effects calipers with opposed pistons ie Cortina style not the floating calipers used on most modern cars.

This type of spongeyness often only appears some time after pushing the pistons pack to fit new pads and gets gradually worse with mileage.

Bent or twisted caliper brackets also present similar symptoms, the caliper must present the brake pad as true to the disc as possible, but this mainly affects only DIY disc brake conversions with home made brackets.

One way to track down which caliper is causing the problem is to get an assistant to pound the brake pedal on and off as hard as possible while you check each caliper by placing your had against it and the disc at the same time --- if you feel a tiny amount of flexing you have found the problem.




In any event the master cylinder is very easy to test just uncouple the pipe at the master cylinder, fit a bleed nipple in its place and give it a quick bleed, then under test the pedal should be rock solid apart from any flex in the pedal box mounting.



Tip to avoid losing too much fluid before uncoupling the pipe top the master cylinder up to the very brim and stretch a clean polly bag over the top before replacing the lid trapping the bag under the lid to make a perfect airtight seal. I you do this only a tiny drop of fluid will come out while the pipe is unscrewed and it saves a lot of bleeding.






[Edited on 18/8/08 by britishtrident]

GregSL75 - 18/8/08 at 04:07 PM

Funny you should say that, but I was having trouble getting the front right brake to lock at scrutineering the last couple of meetings (locks fine when reversing to have another try)

I thought it might just be mud in the caliper, but it sounds like that side is worth a strip.

When you say cortina style caliper, I think it's on cortina uprights and ford disks so it could well be 'cortina style'

Cheers for the tip!

britishtrident - 19/8/08 at 07:55 AM

With Cortina calipers (Girling M16) almost certainly a sezied piston, or the pad stuck in the caliper.

Take 1 pad out at a time, put a screw driver or tyre lever between the disc and piston a get a helper to give the pedal a push to about 50% travel, you should see the piston move. Replace the pad & repeat for each piston & caliper.

If a piston is stuck just get an exchange caliper it is easier and cheaper than trying to fix it.

If you don't find a sticking piston check the pads are free in the caliper, if not grind or file about 0.25mm of width off the metal back plate of the pad to give it extra clearance in the caliper and cleean any crud off the caliper guide slots.