C1 - Master Cylinder & Heater Box

[studiog]

Disassembled my master cylinder today and I have a rebuild kit on the way. Does anyone have any tips or recommendations regarding the rebuild procedure for the original type master?

Also disassembled my heater box. The core seems to be in good shape and flows water very well. I am going to pressure test it tomorrow and check for leaks. I will also pressure test the heater control valve. Is there a way to check if it is operating properly? I know this valve controls the flow of coolant to the heater core but I'm not sure exactly how it functions... when it opens and when it closes.

Thanks for any help.

 

[RugHead]

I would brass sleeve the master cyl. while it's apart.

 

[stepinwolf]

This would be my suggestion

This hobby of ours, dictates that we do as much of the labour as we can, and then farm out the balance to the professionals. Brakes, as far as I'm concerned fall into the second categories. Rather then try and do the rebuild yourself, you would be better off sending it out to one of the speciality shops, and have it done in stainless at the same time. Few dollars are involved, you will be assured it will be done correctly, and it will be one more item, you will never have to address again.

I know some will disagree ( I don't need to hear it ) but this is my 2 cents

Steppinwolf

 

[IH2LOSE]

Sorry Gary but I am with stephinwolf on this one,(I am not saying you have to send it out)

BUT


Allthought I am somewhat skilled working on mecanical things,When it comes to a master cylender there is no body better to do then white post restorations.

Now as for your heater core I was going to suggest a new one,but after I looked up the replacement price from paragon $100.00 (I know how much a total restoration cost ) I guess if the old one holds pressure you could try it and next year or the year after put in a new one after your wallet has healed.

One of the things that happens that even with a flow check it does not tell you if the entire core is flowing or just the top half (because the bottom half is glogged with sediment)

But even with this information I highley doupt the heat will be need too often

Lastley the most you have to pressure test it with is 14lbs pressure anything higher and the radiator cap will open up when its connectect to the system

 

[vintagecorvette]

I rebuild a lot of master cylinders. You only have a problem if it has pitting. If it has pitting then it should be sleeved, if no pitting, there is no real need to sleeve it. You should hone it out and install a rebuild kit. Rebuild kits are easy to get. oWEN

 

[stepinwolf]

I agree to dis-agree

Sorry Gary but I am with stephinwolf on this one,(I am not saying you have to send it out)

BUT


Although I am somewhat skilled working on mechanical things,When it comes to a master cylinder there is no body better to do then white post restorations.

Now as for your heater core I was going to suggest a new one,but after I looked up the replacement price from paragon $100.00 (I know how much a total restoration cost ) I guess if the old one holds pressure you could try it and next year or the year after put in a new one after your wallet has healed.

One of the things that happens that even with a flow check it does not tell you if the entire core is flowing or just the top half (because the bottom half is clogged with sediment)

But even with this information I highly doubt the heat will be need too often

Lastly the most you have to pressure test it with is 14lbs pressure anything higher and the radiator cap will open up when its connected to the system

Gary,

I wouldn't be comfortable if I didn't add my two cents to IH2LOSE comments regarding the heater core. It's replacement in a newly restored Corvette, is not something you would wish on anyone. At 100$ a pop for a new unit, it's cheap insurance against future disaster. The replacement is labour intensive, dirty, and a very messy job. A good part of the under dash area must be removed, often the heater hoses are stuck, and susceptible to damage during their removal, and as incing on the cake, all the anti-freeze you were not able to remove from the core, will end up on your new carpets, during the turning, and twisting motions you will go through in trying to wrestle the complete heater box from under the dash. If you think the SOB was hard to get up into proper position during the re-build, wait till you have to get it back up there into position in a completed car

Trust me, it's really not a fun thing to have happen too you. The 100$ you will initial spend is cheap insurance against this type of happening.

My humble opinion
Steppinwolf

 

[jose]

silicon fluid

If its pited then sleave it in stainless even the wheel cylinders and dont forget to use Silicon break fluid, this fluid will not collect moisture and damage your master or wheel cylinders like others, great for culch systems also.

Have used it on my Harley and will be using it on my 59, it has not been replaced or toped up in 8 years and if its leaks somewhere it wont damage any paint, cant ask for more except maybe a better price..........

 

[studiog]

Thanks all for your comments and tips. They are very helpful and will allow me to make more educated decisions about replacing these parts.
Gary

 

[studiog]

Update: Heater core leaks like a sieve so it will definitely need replacing or recoring. The master cylinder looks to be in good shape. The bore looks good but is discolored in a few small places but I can't feel any pitting when I run my finger across it. So I think I will hone it and see how it looks after that. I already have the rebuild kit and the hone so it makes sense to me to go ahead at this point. I have done many brake cylinder rebuilds in my day so the master doesn't scare me. I will use the silicone brake fluid too as this also makes sense but it isn't cheap. Thanks again guys for all the help.

 

[IH2LOSE]

Just as well Gary,It really would have stunk having it all together and had a failure.

Whats another hundred in the sceme of things?

 

[studiog]

Just as well Gary,It really would have stunk having it all together and had a failure.

Whats another hundred in the sceme of things?

Larry, You are absolutely right! I'm almost glad it was bad.