So I flew back to Iowa this last weekend and am going to go through my brake system on my 1978 vette and hopefully have time to get through the vaccuum leak for my headlights. What I am looking to do tonight (which I have never done before) is take off my master cylinder and hopefully get it replaced and clean the calipers and check all lines. I am quite sure that there is a leak somewhere and I have to look into finding it. The car has been sitting in my dads garage for the last ten years. I also have to go to a remote location to get a lot of the tools I will need. Can anyone give some guidance on how to remove the master cylinder along with what tools I may need? Sorry for being a n00b but I wanna try and tackle it myself and not pay someone an arm and a leg.

 

Any time you're working a brake system you want to use Line Wrenches in a variety of sizes starting from 1/4 inch going up to 1/2 inch. Most common fittings are going to be 3/8 and 7/16 inch. Line wrenches will prevent the striping of any of the brake line fittings going into the Master Cylinder and Calipers that have sat a long time. Soak them overnight if they are tight with Liquid Wrench or PB Blaster or WD 40 Penetrating oils. These will cut thru some of the rust.

For most other parts on the brake system have a set of wrenches and sockets ranging 1/4 inch to 11/16. I have found working on my 1977 I run across bolts that are 11/16 and most wrench sets do not have an 11/16 they skip from 5/8 to 3/4.

Most popular bolt sizes are going to be 1/4 5/16 3/8 7/16 1/2 9/16 5/8 11/16 and 3/4

Most common leaks will be in the rubber lines going from the frame to calipers, caliper seals and master cylinder seal but they can happen anywhere in the brake system.

Bring at least 2 quarts of brake fluid with you if your out in the middle of nowhere. Just flushing out my system I went thru a quart. 3 or 4 cans of brake cleaner. I like to use a bleeder hose then put it into a can so I do not squirt brake fluid everywhere. Brake fluid will eat the paint off the car.

The Corvette master cylinder sits level enough it can be bench bleed in the car but it is messy and preferred method is on a bench with a vise. If doing in the car 2 people are needed and lots of rags.

Someone might be able to provide more information and add to this.

 

take pictures before you take any parts off, so you can reference back if you have questions.

 

Very important:
1. Start at passenger rear wheel (Right rear) first.
2. Then go to drivers side rear.
3. Next do passenger side front.
4. Finish off with the drivers side front.

If you have a hard time releasing the brake bleed nipple (s) OR any of your nipples become distorted/damaged OR you notice rust (yes, remove some nipples and you may see rust in threads) you can replace them at your local NAPA or parts store. ($2.00 ea)

 

These are all great recommendations. Maybe a small, hard plastic-tipped hammer also to help shock any penetrating oil bathed threaded joints into submission but use with prudence. Those small fittings shouldn't require a lot of force to break loose and rounded fittings only make the job more frustrating and costly.

Good luck.

 

You will need a 6 point 5/8 half inch drive socket and a breaker bar.

 

 

I performed a bleed last weekend.
Replaced ALL brake fluid.

YES; I had to replace 2 nipples, 1 on the right rear and 1 on the left rear. I will post a pic.
I had to remove the Left Rear Caliper, put it on the bench and remove it w/ vice grips.
Yup, siezed, rust on threads etc. Horribly distorted before I even tried.

Previously it had been damaged.
(I thought about the "quik-bleed" nipples bt thought it was overkill)

 

Ok guys thanks for all your help so far. I have gotten as far as taking off the master cylinder, removing all wheels and putting the car on jack stands. I borrowed some line wrenches from a friend here in town to remove the lines which is on my list to do today. I saw the rotors on the front have like studs going through them and they are not there on the back. These studs are basically parallel to where the bolts are for the lug nuts. I was wondering if those stay in there or I will have to remove them in order for rotor removal?

 

If they have not recently been changed (within about 5-7 years), you should replace ALL four of the flex hoses that connect each caliper with the metal brake line. These go bad from the inside...you cannot detect any part failure from the outside. And, a deteriorating flex hose can allow that brake to stay partially applied and create a LOT of heat...even to causing a brake or tire fire!!

Changing these flex lines, purging all of the old brake fluid and replacing (or rebuilding) the master cylinder are all things that need to be done when refurbishing your brake system.

 

do you think a guy can do all of that in a day? How much of a pain is it?

 

I would not re-build the calipers unless they were leaking.

So; that being said, yes, you have plenty of time to change the 4 lines and bleed the system.

 

Depends on how tough it is to get the lines loose. The connections between the metal lines and the flex lines is the 'problem' area. You definitiely MUST have a top-grade of tubing wrench for that size hex nut. A 'cheap' tube wrench will spring open under the load that is needed to pop that connection loose.

And, if you do damage to that nut, you may end up cutting the metal line to get it loose....then you need to replace the metal brake line.

Get the right tools; prepare well for the work being done; and proceed with care. If you do those things, there will not be any problem.

When you pull the flex hoses off, you will be able to assess the condition of the brake fluid. If it is just dark in color, but has no rust or particulates in it, and you have checked to see that you can put full pedal pressure on the system and you get no leakage from the calipers, you might get by without replacing or rebuilding the calipers. BUT, I would recommend that you open at least ONE caliper up....just to see if you have SS-sleeved bores (or not) and what kind of seals are on the pistons. But, that decision will be up to you. If the fluid is very nasty with "stuff" in it, you MUST open the calipers and rebuild them...or just replace them with exchange parts from the local parts store.

If you have no caliper leaks with full pedal loading, I would not feel bad about NOT opening them up. You just need to realize that future regular use could generate a leak at any time.

 

Back in the old days they used to Rivot the rotors to the hub assembly and the rivots have to be drilled out so you can replace the rotor. It is easier to remove the whole hub assembly to drill out the rivots.

They do not have to rivoted back in which is why you saw the holes in the rear rotors.

Inspect the wheel bearings on the front while you have them off. Most of the time you will need to replace the wheel bearing the bearing race. The bearing race can be tapped out with a punch. Putting the new ones in should be done with a plastic mallet or piece of wood so not to damage them. You will not be able to get to the rear wheel bearings and that is a lot of work with special alignment tools.

 

Best advice

Cuz "I'm stupid" and I ALWAYS forget how it goes.

 

Why do you want to remove the front rotors? You may be able to have them resurfaced AKA turned. Turning rotors can be done without drilling out the rivets. Pictures of the rotors might help us tell you if they need to be turned, replaced or maybe nothing done to them.