Rebuilding a Master Cylinder

[nobody]

I have a reasonable supply of those if you want any. hmm Gilbert, plastic works, Hj Engineering. Oh be nice to the bank tellers. One is my daughter there.

[73 gt man]

Thank you guys, everyone on this site has been great, Nobody I would like to know what kinds of parts you have I saw the thread about the cars out there and will respond on that thread, I would like to get a hold of those brake lines, I am going to flush the entire system this week. The brakes is all that has to be completed to drive it every day. I have not heard of HJ engineering and I am nice to all the bank tellers.

[namba209]

Sean, OGTS has a complete brake hose and line kit, if you wanted to change out the whole system. Check out their on-line catalog at www.opelgtsource.com. HTH.

[Lindsay]

A1 Cardone Remanufactured GT Master Cylinder is $34.79 at www.rockauto.com. Rebuild kit is $27.29.

Used (2) A1 Cardone remanufactured master cylinders without failures.
Never understand why owners rebuild their GT Master Cylinders unless it gives them satisfaction and piece of mind.

[73 gt man]

I did not know about the companies that offered the parts next time I will just order it. Namba thanks for the info I will call them today.

[namba209]

Lindsey, RockAuto doesn't have any GT MCs, that's where I tried to get one. I ordered one on line, three days later got the call, there are none to be had. Gil has about 30-40 cores at Cardone to be rebuilt, but no word on them as yet. They've been there for months according to Gil/Dennis. I was lucky kinda, OGTS had a few euro MC cores, I'm gonna be putting one my GT until they get the rebuilts back.

[73 gt man]

A brand new MC showed up on Ebay I am sorry but forgot to mark it. It was up to about 90 dollars but it is brand new not rebuilt.

[namba209]

Sean, if it is a new MC, it is probably NOS, as in "new old stock" which means it will need a rebuild kit unless it has been sealed from the environment for all these years. $90 right now plus a rebuild kit would put it way above what OGTS sells their rebuilt MCs for when they have them. Right now I'll opt for a euro design that doesn't have the pressure differential chamber below the piston chamber for the brake lite ground, just to have an operational car. I am on the waiting list at OGTS for an MC and other parts they don't have available right now. The thing is, I know when I get a part from them, it will work as advertised.

[73 gt man]

Thanks Ron for that heads up, I did not even think of that and it makes perfect sense, I did call OGTS and they are sending the new connection that I screwed up as well as a few other goodies. Again thanks for the help to all.

[shade tree]

The master cylinder listed for the GT at rockauto is for a 1.1. Are the brake systems the same?

[namba209]

Shade Tree, I don't know if the MCs are the same for all GTs, but a real quick and dirty way to find out, is, check the on-line catalog at OGTS. They list all the parts for everything they carry along with the prices and if memory serves, they have the MC listed for the 1.1 and 1.9 engines, so I am guessing they may be different.

[sawdust]

Originally Posted by namba209 J....here's the breakdown on the the rebuild Kit I got from OGTS...... HTH.

Does anyone have a breakdodwn drawing on what is in the PB Booster. I would like to know how brake fluid can get into the engine and if it is repairable.

Thanks for your assistance.

[Anonymous D]

Fluid in the brake booster, means the front seal on the master cylinder has worn away. The resulting buildup in the booster makes its way into the intake manifold via the long brake booster vacuum hose.
You need to drain the fluid from the booster and the hose (and the hoses' inline one-way check valve too), and replace that seal on the master cylinder. Booster evalustion depends on whether the rubber diaphragm is intact and air-tight, and if it has not been eaten through by brake fluid over time (test is usually performed on the car, with a vacuum pump/gauge).

Master Cylinder rebuild instructions, including procedures that would have prevented some of the complications noted earlier in this thread, were printed in the OMC Blitz in the June 2004 issue.
Cost for a reprint: All of a budget-busting $$two$$ dollars (including US postage).

This set of instructions, are not the same as those commonly included with the rebuild kits (you won't get this information from a generic dealer like RockAuto, either!), but are instead more comprehensive, as they were written from experiences during an actual disassembly and rebuild job.

[sawdust]

Originally Posted by Anonymous D Fluid in the brake booster, means the front seal on the master cylinder has worn away.

Recommendations please.
should both the MC and Booster be taken out or just the MC. The manuals say remove but not how to remove. Sorry, ten thumbs here.

[namba209]

Here's a hint, there's two bolts holding the MC to the booster. There are four bolts holding the booster to the radiator support and to take it out, you have to disconnect the brake rod from the pedal to the booster. Best bet, and it's a bit tight, you can pull the MC from the booster by tweaking the reservoir just a bit.

[sawdust]

Thanks namba209.

I got the MC out first. Would rather have done a rectal exam on an elephant.

Now I want to get the booster out so I can drain the BF out of it. I need guidance on unhooking brake push rod. Or suggestions on draining it with it still mounted.

[Anonymous D]

You can use a pair of open-end wrenches (either 17mm or 19mm, as I recall), to detach the booster from the rod and pull it from the car, or drain the booster in place with a siphon pump/hose and/or sheets of paper towels rolled up and inserted through the round port for the vacuum hose inlet elbow.

When reassembling to the master cylinder, install new front o-ring seal (costs about $3) and consider adding a thin ring of Silicone RTV sealer on the area external to the outside of that o-ring (for added sealing).

[West Coast GT]

Sneak your wife's turkey-baster out of the kitchen. You'll be able to remove most of the fluid. Get that last bit out with paper towels.

Buy a new turkey baster before your wife finds out you used hers.

[sawdust]

thanks Anonymous D

I got the seal kit from OGTS on the way.

question: there is the elongated nut and a jam nut. just break those two and then what. spin the elongate nut off the threaded rod???

[sawdust]

Originally Posted by West Coast GT Sneak your wife's turkey-baster out of the kitchen. You'll be able to remove most of the fluid. Get that last bit out with paper towels. Buy a new turkey baster before your wife finds out you used hers.

Hey, shes my helper. she's hiding that baster as we speak.

thanks

[namba209]

You gotta be careful when you loosen the jam nut so as not to lose the rod length adjustment. Best way to separate the rod is loosen the jam nut as little as possible, remove the cotter pin and washer from the rod at the brake pedal, slide the rod out of the brake pedal then unscrew it from the coupling nut. The remove the booster. When you're ready to re-installl, mount the brake booster and MC, then screw the rod back into the coupling nut noting how many turns or flats you undid the jam nut. The couplig nut will rotate inside the booster so a close approximation will be needed to get everything back to where it should be. HTH.

[West Coast GT]

Namba209,
That bit about not losing the rod length. How critical are you talking? I shortened mine considerably in November, replaced the MC & Booster in May, then just adjusted the length haphazardly yesterday.

Do I have trouble coming down the ro