Brakes

[66corsaguy]

1966 Corsa:
Right wheel brake cylinder. When brake is applied lightly only rear shoe moves. So I’m assuming cylinder is broken.
Couple questions. Am i supposed to replace as a pair? Meaning right and left wheels?
Also i am assuming this shoe is a goner.

IMG_6382.JPG (84.21 KiB) Viewed 833 times

Opinion on buying LAPS or waiting a week or so for parts from Clark’s
It’s been storming rain for two months in my area and finally have a week of clear weather. Would love to do the mechanic work this weekend and buy local rather than waiting for shipping. But i would rather have the correct and good quality parts. but if LAPS the same as Clark’s than I’ll buy here. Any advice, suggestions and recommendations on brand or parts to buy?

Lastly. Can i measure etc myself for the drum wear and figure out if that’s good to reuse or do i need to buy as a set?

Image1552690487.525091.jpg (91.15 KiB) Viewed 833 times

I really have no idea how old any of this is.

[terribleted]

Ok you would certainly want to replace the shoes on both sides of the axle so they are evenly sized. You could replace just the one wheel cylinder, but, it is best to replace both so that they are as even as possible (and if this side has an issue and the other is old as well it is likely to have an issue soon). Concerning the drum in you photo it is Ok to machine your drums to .030 oversize with standard size shoes and a maximum of .060" using .030 oversized shoes (not sure where you would get .030 oversized shoes) (this data from the 65 GM Corvair Shop Manual on page 5-13). You can measure your drums to see what diameter they are, new is 9.5". GM drums have a 45 degree bevel at the outer edge of the drum into the brake shoe wear surface. I have found that if this bevel has been machine off from turning the drums over the years (so it is a Square edge like yours) that the drums are oversized and should be replaced. (this bevel would take about .060 of machining to go away). Just because a drum has bevel in it does not mean that it is good as a very good brake shop may re-bevel the edge after machining. So if your measure 9.5+ .030 or less they may be ok , but I doubt they will. The chattering wear I see on the shoe also could be caused by drum being oversize. I would replace the shoes and both drums and actually unless they look perfect and new (replaced) I would also replace the spring kits, adjuster levers and adjusters.

[66corsaguy]

Yeah the more i look i think it’s all toast.
Makes sense to do both sides as they are most likely the same age. And i should check the rears i guess too. When i spin the wheel i can hear/feel the tension in uneven ways so guessing out of round also?
I’ve always noticed this while driving that when i am moving slowly there is an “out of round” feel so buying new drums and shoes etc will probably resolve a lot of things.

I think shipping on this is gonna be a lot from Clark’s. Is it a bad idea to buy from Local Auto parts? Sure i want to support Corvair vendors —and i do —-but I’m in California and Clark’s is in Mass i think, cant get much farther!! — the shipping is just really a lot for such heavy objects like drums. Should i eat it or any other ideas?

Lastly. Would it also be time to change out brake lines and bleed? The lines don’t look very old but I’ve had this car for 5 years already....

[County98]

I'm not a pro, but you're going to need to open the lines and bleed anyway for wheel cylinders. If rubber parts of brake lines look dry rotted (or they're original) might not be bad idea to knock it out.

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[terribleted]

I'm not a pro, but you're going to need to open the lines and bleed anyway for wheel cylinders. If rubber parts of brake lines look dry rotted (or they're original) might not be bad idea to knock it out.

Sent from my SAMSUNG-SM-G891A using Corvair Forum mobile app

Yes indeed I forgot to mention those. If the hoses do not look new replace them as well (and do not forget the copper sealing washers for the front hoses if you are replacing them...wheel cylinder end uses them). It is a good idea to try to remove the steel lines from the hoses and wheel cylinders before you order parts if possible. Often they are rusty and if the shear off when removing them then you are waiting again. Local parts houses can be hit or miss on these parts. IF they can get them at a reasonable price AND they turn out to be the right parts you should be ok. I would get my shoes from Clarks for sure as they seem to work ok. I have heard many stories about linings being to hard to function well and since I have not had this issue with Clark's I assume these are coming from local sources. I would also get my adjusters and spring kits from Clark's or another Corvair vendor as well as I have seen incorrect parts in these local purchased before. I have sourced proper drums locally in the past but it was not easy and I did not save any cash really just a little time.

[66corsaguy]

I'm not a pro, but you're going to need to open the lines and bleed anyway for wheel cylinders. If rubber parts of brake lines look dry rotted (or they're original) might not be bad idea to knock it out.

Sent from my SAMSUNG-SM-G891A using Corvair Forum mobile app

Yes indeed I forgot to mention those. If the hoses do not look new replace them as well (and do not forget the copper sealing washers for the front hoses if you are replacing them...wheel cylinder end uses them). It is a good idea to try to remove the steel lines from the hoses and wheel cylinders before you order parts if possible. Often they are rusty and if the shear off when removing them then you are waiting again. Local parts houses can be hit or miss on these parts. IF they can get them at a reasonable price AND they turn out to be the right parts you should be ok. I would get my shoes from Clarks for sure as they seem to work ok. I have heard many stories about linings being to hard to function well and since I have not had this issue with Clark's I assume these are coming from local sources. I would also get my adjusters and spring kits from Clark's or another Corvair vendor as well as I have seen incorrect parts in these local purchased before. I have sourced proper drums locally in the past but it was not easy and I did not save any cash really just a little time.

Ok. Well it sounds like Clark’s really is the way to go. I’ll have to purchase quite a bit and going to look at my rears now also and see if i should order 4 and knock them all out. I think I’ll pretty much buy everything and replace including the steel lines you mentioned. I have no idea when the last time anything was replaced and i plan on keeping the car a long time.

If anyone has any other suggestions for me in terms of items to buy or way to do this i would love to hear. I’ll be making my list in the next couple of days and i would rather replace everything and start fresh.

I wonder if Clark’s has a brake kit that includes everything you need for complete brake overhaul


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[terribleted]

If it does not have a dual master cylinder conversion yet I highly recommend it. Quite a bit safer. If there is a leak or a hose bursts you still have some braking, not a lot but some is better than none.

[joelsplace]

If you are replacing the whole system you might consider going to Dot 5 fluid. Lots of people recommend it. I just use Dot 4 myself but am thinking about switching. If you go with 5 be sure to put a tag on the master cylinder to remind you or whoever puts fluid in it in the future.

[acarlson]

I rebuilt all 4 brakes on my '65 Corsa. Here's what I did (it's been working fine for me):

viewtopic.php?f=225&t=12705&p=87023#p87023

Alec

[66corsaguy]

I rebuilt all 4 brakes on my '65 Corsa. Here's what I did (it's been working fine for me):

viewtopic.php?f=225&t=12705&p=87023#p87023

Alec

Thanks for all the advice and this posting. Very helpful.

[County98]

I redid mine as well, somewhere early in my thread, if you need more pics.

Everything always turns into a bigger and bigger hole when you start working it. Up to you where to draw the line. My brakes needed a full do over, so went with the clark's package on dual master, new lines, etc.

Brakes are pretty much on the "need" list, so dual master and at least anything rubber is a good start.

[1949chevy]

if you checked the wheel cylinder without the drum on and just one shoe moved...that would be the weaker springed shoe...that would be normal. You would have to put something on the shoes like a small dab of something on the complete shoe or the drum area, then apply the brakes hard and see if you are getting both shoes against the drum. Heavy chalk might work. I doubt the wheel cyl is bad unless its leaking. If just one shoe is working, you might can rock the drum with the brakes applied. Put the lug nuts on and take a steel bar, put it between the nuts so as not to harm the threads and try and rock the brake.

And wheel cylinders can be rebuilt as long as the corrosion is basically toward the center of the bore, most older used wheel cyl with have this corrosion in the center...you can get the rebuild kits at any local car parts place. I have done many rebuilds, even on 4 piston Corvette calipers without the first hint of problem. I have had that car 46 years. But you would have to have a little wheel cyl experience, otherwise, buy already put together parts. I use a small wheel cyl stone hone and give it a little clean up, usually works great on worn wheel cylinders.

Good luck.