Brake Master Cylinder leaking - HELP!

[flux3d]

While trying to get everything ready for the MOT booked for the 3rd of Jan I noticed a pool of hydrolic oil on the garage floor. Now I've had problems with the brakes becoming spongy and lacking in response since picking the car up from Southampton. Increasingly they seem to "fail" and I have to push further on the brake pedal in order to get enough stopping force. I'd checked the master cylinder and it was topped up fine. However, looking today the level was almost to the minimum. I decided to jack the front of the car up and take the wheel off, plus remove the cover above to inspect the MC in more detail. There seems to be a really bad leak where the MC connects to the servo housing. (need to rotate the image by 90 degrees)



The fluid has been running down the front and collecting near the tank, damaging the epoxy in places. I've removed the damaged epoxy and cover for the tank, plus cleaned out any other fluid on the frame.




I've removed the MC which seems to be leaking out of the back of the ram. There was a fair amount of fluid in the connection point at the servo as well.



I have a few questions:

Should I completely replace the MC? The rest of is seems fine, although it could do with a clean up and re-paint.

If I'm not replacing it can you get hold of the seals, and if so does anyone know where I can get hold of the asap?

Should I remove the servo as well and re-paint? Seems like a good idea, and would complete the job.

What is the best thing to repaint the areas effected by the fluid? I have a waxol black underbody paint I was thinking of using. Considering the under body already has a black sealant applied is this the best approach? How should I treat the rust on the effected parts?

The frame seemed in excellent condition under the black coating (well other than the area effected, which comes away with white spirit. It seems to have done a good job of protecting the epoxy and frame, even if many people hate to see it on DeLoreans.

Without brakes the MOT on the 3rd looks like an impossibility.

[Chris Williams]

viewforum.php?f=26

Quote:Should I completely replace the MC? The rest of is seems fine, although it could do with a clean up and re-paint.

If I'm not replacing it can you get hold of the seals, and if so does anyone know where I can get hold of the asap?

I would, is it worth taking a risk with brakes?? I have just done the clutch M/C and you would not believe the damage water can do to the bore.

Quote:Should I remove the servo as well and re-paint? Seems like a good idea, and would complete the job.

Might as well, can check it out for fluid and get it cleaned up!

I use POR 15 paint for the frame from Frosts I think. really good stuff and a good match for the Grey, but as it's covered in Waxoyl then I dont suppose it matters to much!

Good luck and let us know how you get on

Chris

[flux3d]

Cheers Chris. I'm thinking of removing the black stuff. Comes pretty easy with white spirit, but still not a pleasant job. Seems to have preserved the rest of the frame really well. Not sure. Looks better as its original grey, but maybe painting it in waxoyl will preserve the frame better in the long run. What do you think?

[Chris Williams]

Quote:preserve the frame better in the long run. What do you think

Mine has the black stuff splattered all over it too, IIRC a batch were done in the US in the first place so it's not that odd to see it and to be fair at the end of the day, other than looking odd it cant do any harm can it?

Chris

[Nick H]

I would forget a rebuild kit. I tried rebuilding my brake master cylinder it still was not right afterwards so I replaced it with a new one.

I found a replacement which is 50/50 bias from a Saab 99 I think. It works fine. Check out the parts section there is a link to the parts place I used. Think it was about £50.00 and was really fast shipping.

Be careful with the reservoir as they are hard to come by.

Regards
Nick H

[MikeWard]

Nick H Wrote:Be careful with the reservoir as they are hard to come by.

If anyone has a need, Ed has 'replacement' reservoirs available:
http://www.delorean.eu/catalog/product_ ... 5db0a8158a

[Nick H]

Nice info Mike.
I needed a new one when I changed my MC. Got the last one Lucas old stock that a classic brake specialist had on the shelf.

I notice my link in the parts section is not showing the Saab MC any more.
However if you do a search using the cross ref. info several suppliers appear on Google. About £70 quid now :roll: .

Regards
Nick h

[Chris Williams]

viewtopic.php?f=11&t=4387

There is an Ebay one I linked to in this topic: viewtopic.php?f=11&t=4387

Chris

[dmc4087]

My frame needed a patch below the M/C reservoir - this was carried out during the frame off.

The plate below the fuel tank was also badly corroded, and in the end I replaced it.

Might be worth having a wee look to catch anything before it gets bad.

[flux3d]

All sorted, well just about. There was some surface damage to the frame and tank cover, but nothing major. That black gunk covering the frame seemed to have worked very well. It just needs a bit of tidying up and reprinting, which I'm doing at the moment.

The main thing is that I've replaced the MC with a new one from DMC, plus taken out the servo and reprinted that. Bled the system all round and everything seems to be working really well now. Just taken her out round the block and the brakes are much better.

Another job down, and the MOT is tomorrow. Fingers crossed for that one!

[Guinney1971]

great stuff Mark, good luck for the MOT - make sure your handbrake is nipped up to the max