Rebuilding a Master Cylinder

[West Coast GT]

Namba209 - Thanks for the heads-up. I'm concerned the bolt through the banjo fitting may be deep enough to crush the pintle or nipple inside the MC outlet. Or, the pintle/nipple may not allow the bolt to seat deep enough to allow the copper crush rings to form a seal.

Do you recommend against installing an extra copper ring between the MC & banjo, or between the banjo and the bolt head? I've never doubled up on these before and have my doubts they would seal. Your opinion?

Lindsay - I'm heading down the road real fast towards installing a BMW master cylinder because I'm running out of viable solutions. My preference is to keep things fairly stock to make life easier on repair shops I might use in the future and/or the future owner of this car. I really don't want to be the dreaded evil PO.

[namba209]

A couple of things to look at in this regard. Adding washers to the bolt head side may block the groove/hole in the banjo fitting, that is the hole in the bolt and the groove on the inside of the copper sleeve. Second, you're correct in presuming if the bolt bottoms out, there may be no sealing of the crush washers. I'd screw the bolt in to see where it bottoms out and add the crush washers to insure it doesn't bottom out and just have one crush washer under the bolt head. Again, if that doesn't work, you're looking for another MC. Give Gil or Dennis a call at OGTS and see if they have a new, or used MC and you can rebuild it. They did that for me one time, and I ended up with a euro MC with no chamber under the main bore for the brake failure switch contact, but it was no big deal, I can sure tell when my brakes are failing.

[West Coast GT]

Thanks, I had not considered that additional copper seals on the bolt head side of the banjo would offset the groove and hole.

Adding the banjo fitting to the lower brake line interfered with the existing banjo fitting of the upper brake line.

So it's back to new fittings and a spliced line. I practiced my first double flare tonight. Not pretty - but she set well in the MC. Tomorrow night I need to make two flares. The tough one will be made in the nose of the GT. I've got ahold of a brake line union. Once I get the splice all set up I can attach the front lower brake line, install the MC, then connect up the brake lines more easily than trying to connect it by touch only while stretching across from the other side of the car.

If that fails, I'll call OGTS, but there's been a back order going on since November or December. I haven't checked in about two months - so....

[namba209]

Originally Posted by West Coast GT Adding the banjo fitting to the lower brake line interfered with the existing banjo fitting of the upper brake line.

One thing neat about banjo fittings, you can rotate the barrel around the bolt. If your top brake line is just a bit bent or has a curve in it, you can move the barrel enuff to allow a fitting to be installed in the lower fitting, maybe.

[West Coast GT]

I looked at rotating the fittings in several configurations and decided to leave the "other" two brake lines as is. With my luck, once I disturb them they'll end up getting cross-threaded too.

I realize it sounds as though I'm asking for help, then turning around and shooting the ideas down; actually, it does sound that way to me too. But I am evaluating each idea. And it's handy to have the fall-back strategies because my current direction keeps failing.

And I've learned to make a double-flare connection now - not a particularly good one, but it seals and I'll get better at it. The next trick will be the one-handed double-flare performed in front of the radiator.

[wayne70gt]

Originally Posted by West Coast GT The next trick will be the one-handed double-flare performed in front of the radiator.

Is this a gymnastic move to impress you beloved Opel?

[namba209]

Originally Posted by West Coast GT I looked at rotating the fittings in several configurations and decided to leave the "other" two brake lines as is. With my luck, once I disturb them they'll end up getting cross-threaded too. I realize it sounds as though I'm asking for help, then turning around and shooting the ideas down; actually, it does sound that way to me too. But I am evaluating each idea. And it's handy to have the fall-back strategies because my current direction keeps failing.

All your have to do to relocate the lines, is loosen the bolt a couple of turns and rotate the barrel, with the line attached, to a new position and tighten down the bolt. That way the bolt doesn't come out of the MC, so it "shouldn't" be possible to cross thread it. I have no problem with you shooting down anything I recommend, you're there, I'm not, and, you can see what's going on. If I was there, or anyone else, they might see something different than what I recommend from here. Congrats on making the double flares, they've always been a PIA for me to do and look good, but functionality is the key with those.

[blancojp]

Just a quick note, the BMW 325i master cylinder with the fittings on the left side is 3/4" longer and will interfere with the drivers side headlight. The fittings and brake line will stick out about 1" into the bucket area and will not allow the bucket to rotate properly. This happens even with banjo fittings and a few other inventions.

Just FYI.....

[Lindsay]

Originally Posted by blancojp Just a quick note, the BMW 325i master cylinder with the fittings on the left side is 3/4" longer and will interfere with the drivers side headlight. The fittings and brake line will stick out about 1" into the bucket area and will not allow the bucket to rotate properly. This happens even with banjo fittings and a few other inventions. Just FYI.....

Are all BMW master cylinders fit problems in a GT? Glad you mentioned!
Previous information was lacking noted critical details for GT.
THANKS!

[West Coast GT]

It Lives.

After a four-week saga, I've got brakes once again and took the GT out for a short test last night.

Anyway, several lessons learned:
1. Even a NOS master cylinder should be rebuilt before use.
2. Don't continue forcing a cross-threaded connection. Stop, back it out, and if it's gone too far, bite the bullet and fix it.
3. Listen to those more experienced than you, they can save you a world of grief.

Matter of fact - I'm going for another drive right now......

[BQS4]

Originally Posted by West Coast GT It Lives. After a four-week saga, I've got brakes once again and took the GT out for a short test last night. Anyway, several lessons learned: 1. Even a NOS master cylinder should be rebuilt before use. 2. Don't continue forcing a cross-threaded connection. Stop, back it out, and if it's gone too far, bite the bullet and fix it. 3. Listen to those more experienced than you, they can save you a world of grief. Matter of fact - I'm going for another drive right now......

In one simple phrase..."experiance is the best teacher"

[Lindsay]

My father was a machinist. Dad taught me to hand tighten fasteners and connections to reduce possibility of cross-treading. Of course when parts do not align, it is tempting to put the wrenches on to persuade connection/ joining. If wrenching is way too tight, back out and check.

In 1995, local import parts store had excess inventory of GT master cylinders and offered good pricing. Found out after failure(s) that internal seals were defective. Opel GT Source helped with advise to rebuild the NOS master cylinder.

A1 Cardone (remanufactured) master cylinder purchased, July 2002, is still stopping my GT. Never would have predicted that GT master cylinders would be so difficult to find, due to shortage of cores.

[trailblazer2727]

Just got home from NAPA. Ordered a master cylinder rebuild kit for my 1.1 GT($36.00 plus Pa. sales tax) Nationwide, Napa lists approx. 30 rebuild kits still on stock for the 20.64MM bore Master cylinder, if anyone is interested. Rich

[ZmokE]

This week i received an MC rebuild kit from Splendid Parts.
This kit contains also one small crush washer (inside diameter 6.1mm, outside 8.4mm ) and i don't know where it belongs to.
Is it possible that it goes into the MC where the brakeline for the left diskbrake is connected? This brakeline is not connected with the so called banjo fittings.
Thx.
Rini.

[ZmokE]

Nobody??

[BQS4]

Rini;
Can you supply a picture?

[ZmokE]

I just make one.
In the left corner the crush washer.
Is it possible that it goes inside the MC, there where the left brakeline is connected (the area that is lightened).

[BQS4]

Rini;
It's possible it goes right there, as the fitting just behind it has one too. That washer is like the ones Opel uases for the trans cooling lines that go to the radiator of an automatic car. It can't hurt to use it there.

[hrcollinsjr]

All of your brake lines are double flared and should be self sealing with no washers. The only place I can think of that you would need that style washer is on both sides of the banjo fittings. I don't recall any internal metal seals at all in the the M/C. If you have an extral seal then it was just an extra seal. You were lucky the next guy may be short one seal.

HTH,

Harold

[ZmokE]

There are crush washers on both sides from the banjo fittings, indeed.
The inside of the lightened area in the picture i attached is not flat, but has a kind of ^ shape. So i don't know for sure if the washer is on the right place there.
Thanks for helping thinking anyways..

[hrcollinsjr]

Originally Posted by ZmokE The inside of the lightened area in the picture i attached is not flat, but has a kind of ^ shape. So i don't know for sure if the washer is on the right place there. Thanks for helping thinking anyways..

That is the "male" half of the double flare seal that mates with the steel brake line. The extra crush washer wouldn't be for one of the bolts on top of the M/C. They can be removed for bleeding (purging air) purposes and IIRC have to be removed before you can completely disassemble the M/C.

Harold