bleeding brakes,,,3 of 4 normal,,,, but the 4th??????

[soth122003]

try rock auto for just the boots. I believe the wheel cylinders come with new boots any way.

 

Joe Lee

[soth122003]

The Dot 3 or 4 is hydroscropic. meaning it pretty much generates a water supply after about a year or so. That and the boots are mainly to keep out dust and debris not seal it from moisture.

 

Joe Lee

[Bryan]

Thanks for the heads up on DOT 5.  I'll be re-doing the entire brake system when I send my motor out for overhaul. Getting all the parts. Does anybody know of any special procedures I need for storing the wheel cylinders & MC?  Might be a few months before I get it together.   On the stuck wheel cylinders,  for $30 a piece I'd just replace them with new. Peace of mind.

[Veemoney]

Harmony,

Most recommend 2 - 5 years so every 2 years is probably appropriate if your using the vehicle and storage is not climate controlled. You can buy the kits for rebuilding the wheel cylinders, most parts suppliers have or can order them. I purchased the wheel cylinder kits from NAPA parts stores here recently which include the seals and new spring. If you haven't already done the master cylinder you should get a kit for that as well since it likely will need attention and is an easy rebuild. 

[harmony]

5 hours ago, Bryan said:

Thanks for the heads up on DOT 5.  I'll be re-doing the entire brake system when I send my motor out for overhaul. Getting all the parts. Does anybody know of any special procedures I need for storing the wheel cylinders & MC?  Might be a few months before I get it together.   On the stuck wheel cylinders,  for $30 a piece I'd just replace them with new. Peace of mind.

That's a good question, Maybe Tupperware?

Makes one wonder when you buy them, how long they have been sitting on the shelf, and if they have been in a controlled environment.

[kencombs]

If you wish to repair the rusted ones, the best way to begin is to degrease.  Remove the bleeder screws completely.  Flush well to remove any brake fluid or solvents and immerse in Evap-o-Rust.  That will get you back to clean metal and the piston may slide out.  If  not, add some penetrant, ATF, Kroil or your favorite and let it sit.   Removing the rust is a must do first step in order get the piston out without scoring.

 

Evap-O-Rust is my favorite as it doesn't require any neutralizing, unlike vinegar, or other mild acids.   But Citric acid or vinegar are good second choices, just rinse and treat with backing soda/water afterwards.

[harmony]

8 hours ago, kencombs said:

If you wish to repair the rusted ones, the best way to begin is to degrease.  Remove the bleeder screws completely.  Flush well to remove any brake fluid or solvents and immerse in Evap-o-Rust.  That will get you back to clean metal and the piston may slide out.  If  not, add some penetrant, ATF, Kroil or your favorite and let it sit.   Removing the rust is a must do first step in order get the piston out without scoring.

 

Evap-O-Rust is my favorite as it doesn't require any neutralizing, unlike vinegar, or other mild acids.   But Citric acid or vinegar are good second choices, just rinse and treat with backing soda/water afterwards.

I filled the wheel cylinders with Deep Creep and left them over night.  That did the trick.  I pulled the ones off the drivers side today and they were not as bad but they did have some rust stained rings, so they were failing as well.  With the one in the picture, I can feel a ridge with my finger print, after I cleaned it out. 

I'd have to go buy a hone to see if I can restore them all.  I haven't done this procedure since the late 60's.  Do I need a lapping compound?  I remember back in the day you could buy over sized cups to be used after honing.  Rockauto seems to be the only one that shows any details on their web site about the rebuild kits,  They mention that the cups fit a 1.125 bore.  Which is probably a factory size because they don't say anything about it being oversize.  But to get the corrosion out of the cylinder, I'm thinking a stock cup might not be big enough.  I noticed that on one of my cylinders on the drivers side the fluid was out as far as the dust boot, so the cup in that cylinder has failed.

[kencombs]

if you use chemicals to remove the rust, the pits shouldn't be deep enough to need OS cups.  That's one of the reasons I advocate for that method over honing as a first step.  Often what one feels is on the surface, not under it.

[harmony]

20 minutes ago, kencombs said:

if you use chemicals to remove the rust, the pits shouldn't be deep enough to need OS cups.  That's one of the reasons I advocate for that method over honing as a first step.  Often what one feels is on the surface, not under it.

Oh ok, I thought you were talking about how to get the piston out of the cylinder when you mentioned the evapo-rust.  Looks like I can only buy that stuff around here by the gallon. I might see if there is something on the shelf comparable in a smaller size.  So how would you apply it in the cylinder?  Would you rub the cylinder wall with 00000 steel wool covered in the evapo-rust? Or submerse it in the stuff and leave it over night? 

[kencombs]

Full immersion works best.   Usually a couple of hours is enough but the amount of rust will determine the time 

[soth122003]

As far as storing the wheel cylinders, Strip them down and apply a light coat of grease or oil to the cylinder. place in a zip lock and store. When ready to use degrease and and clean well then apply a light coat of brake fluid to the bore and assemble then install.

 

Honing I found that using brake fluid instead of lapping compound works very well. Take you time and inspect your work often. To use an oversize cup you would probably have to take out over a 1/32" of material to need one. That can be quite a bit unless you have really deep pits, then replacement is the better option.

 

Joe Lee

Edited December 12, 2021 by soth122003

[harmony]

12 minutes ago, soth122003 said:

As far as storing the wheel cylinders, Strip them down and apply a light coat of grease or oil to the cylinder. place in a zip lock and store. When ready to use degrease and and clean well then apply a light coat of brake fluid to the bore and assemble then install.

 

Honing I found that using brake fluid instead of lapping compound works very well. Take you time and inspect your work often. To use an oversize cup you would probably have to take out over a 1/32" of material to need one. That can be quite a bit unless you have really deep pits, then replacement is the better option.

 

Joe Lee

Makes sense

[Jerry Roberts]

Permatex sells a grease for brake parts , including the rubber parts . Look for Brake Parts Lubricant number 24129 . On Amazon for $7.12