I'm need to bleed my brakes and am looking for all the info I can get before jumping in. Never done this before, but it doesn't sound that complicated so, first question is, 1) is this something for a newbie?
2) below is the procedure from FAQ - is anything missing?
3) does anyone have pictures of where the transparent hose gets attached?
4)does anyone have pictures of where the bleeder valve is?
5)I have Chiltons and am about to start reading, just looking for a sanity check

many thanks in advance

happy weekend

Oscar




"Based on my experience, gravity pressure bleeding is the only way to do it. You might also use a so called pressure bleeder which increase the system pressure more than just gravity.
The point is to keep the pressure inside the calipers above atmospheric all the time.
Use of vacuum pumps will guarantee that you run into problems..... They work fine on other cars, but not on a Vette.

Remove master cylinder cover and fill both compartments to 1/4" below full. Put cover back on or you will have brake fluid all over your fender during bleeding. You don't have to attach the fasteners.


Important: During bleeding, check periodically that you have enough fluid in the master cylinder (MC) reservoir at all times. It's easier to do the bleeding if you get help from a friend to watch the MC level.

Connect a transparent hose to the bleeder and let this go to a bottle on the floor. Start with the left rear inner bleeder valve. Correct sequence is:
Left rear inner
Left rear outer
Right rear inner
Right rear outer
Left front
Right front
Open the bleeder valve until you see fluid entering the hose.
Pump the pedal a few times and watch for airbubbles in the hose. Just keep the bleeder valve open.
Press hard, but release the pedal slowly. If pedal is release quickly this will cause a vacuum in the system that might allow air to get sucked pass the caliper seals. Even with the bleeder valve open this can happen if you release the pedal to fast.
Sounds unbelievable, but it's based on my experience.
When there are no large bubbles to bee seen in the hose, just leave the rest to gravity. The fluid will drain slowly into the bottle while you watch for tiny bubbles. When all bubbles are gone you close the bleeder valve and move to the next. If it's a long time since last bleeding you should wait until you see fresh fluid. Old fluid cause rust in the system.
Your pedal should now be firm and car ready for the road.

 

I just bled mine today, it's easy if the bleeders don't snap off. Soak them in penetrating oil (PB blaster or CRC) first. There is one bleeder on each front calliper, two on each rear caliper. They take a 5/16" wrench. The hose goes on the end of the bleeder.
Here is the right front bleeder and one of the left rears. The other one is hidden in the back of that caliper. They are always near the top.



I open and close the bleeder while my wife presses the pedal. This is the sequence: press pedal, open bleeder, close bleeder, release pedal, repeat until clean fluid comes out with no bubbles. Joe

 

My '80 Shop manual says: Open bleeder, press and hold, close bleeder, release brake pedal. I used this procedure when I bled the rear brakes. Took two passes through the LRI, LRO, RRI, RRO bleeders but the brake pedal is rock hard now.

 

I agree with this method as well. I get my wife, brother, anyone that can follow directions. They get in and the way I do it is to have them pump the brake 3 times. 1, 2, and on the 3rd time hold it. Then you open the bleeder (already having the hose attached and the bleeder broken loose and then lightly closed) and have the person in the car press the brakes until it hits the floor. Then close the bleeder and then let them release and pump the brakes again. I do this until new clean fluid comes through.
Remember to keep the top on the master cylinder while pumping and remember to NEVER let it get below 1/4 full -- NEVER EVER let it go empty.

BIG NOTE: For those that have never worked with brake fluid. IT WILL REMOVE PAINT INSTANTLY UPON CONTACT !!!! Use fender covers near the master cylinder and be very careful with this stuff. Don't use a towel or a shirt as a fender cover as it will soak anything spilled right through to your paint. Use vinyl, plastic sheeting -- anything - but protect that paint.

 

I also agree to this method, but I also heard that corvette calipers are known to have air held in, so when the pedal is being held down, tap on the caliper with a rubber mallet, then release the bleeder screw. I tried regular bleeding and always gotten air in my lines, did it again with the tapping method and brakes never gave me a problem again...I guess tapping the calipers brings the air to the top.

 

Joe, Ted, BSeery and C3 -

all great points - thanks for your time.

couple more Q

1 - is the "bleeder" and the "bleeder valve" the same thing?

i.e. does the tube and the wrench go to the same bleeder?

2 - Chiltons says I need a special wrench to do this - Joe says a 5/16" wrench will do it?

3 - Chiltons says to buy the best brake fluid. is there a particular brand I am looking for?

thanks again for all the tips
Oscar

 

1. yes they are the same
2. unless chilton's can be more specific, a 5/16 box wrench works fine, you have to put it in place before the hose goes on. You should check your bleeders, they might be a different size.
3. just make sure it's DOT-3. perhaps avoid walmart but anything from a major auto store will be fine - wagner is a good brand if you can find it.

 

There are several ways to bleed the system. Once you read up on it you can do it.

You can:

1- 2 man bleed
2-gravity bleed
3- vacuum bleed
4-use speed bleeders
5-use a Professinal pressure system
6-Make a bleeder plate and use your air compressor
7-Use a Motive 1 man pressure system


For years I used the 2 man method and it works pretty good.
I never liked 2-4, #5 cost hundreds, #6 works good but you have to keep filling th eM/C every 30 seconds
That leaves #7, I tried this 2 years ago and was very pleased, It worked better then I expected,of course I was expecting it to be total crap like most items advertised today. It's all I use now and you could use it to find system leaks too. cost about $60 buy it direct from Motive to save the markup costs.



Gary

 

thanks for all the input - new question - I'm doing this in my garage, can I jack up one end at a time or do I need to go buy stands and pull all wheels off at the same time?
thanks again for all the help,
Oscar

 

The wrench they are refering to is a line wrench. This is a combination of a box wrench and an open end wrench, the opening is just large enough to slip over the tubing and allows for max contact on the nut.

Dave

 

Just be sure if you're jacking only one wheel up that you have the hood, doors, and t-tops in an unlatched position (closed, but not fully latched) since you might get flex and crack your body panels. Also, I had this problem until I bought the "O" ring style calipers for my car. I only have them on the front, and I never have to bleed them. I still have to bleed the rears occasionally. Get your rotors turned and it will help with the cavitation that the old style calipers are prone to, they suck air without leaking due to a warped caliper. I haven't done this yet either, but I'm going to try it out on the rears before I pop for new ones ($20 vs $220). Even my very understanding wife sometimes lays down the law...Good luck, you will get real good at this!

 

The GM service manual has the bleed order reversed from the order in the first post. I don't know if it makes a lot of difference, but maybe they should know? Recommended order (as per GM) LF, RF, LRI, LRO, RRI. RRO.

 

Bigfish: are you sure it says to do the fronts first???? Not that i doubt you its just that i have never heard fronts first maybe its just a vette thing.

 

I believe the logic is to displace the air starting at the closest point. That way you won't pick up any air from the side stream (air still present in the front lines). I know it sounds weird, the old school way of doing it is the rears first. Like I mentioned, this is the way my 1974 GM manual has it.

 

For whatever reason, our C3 brakes are a PITA. As you've written, the proper sequence is 1) passenger side rear top bleeder; 2) passenger side read bottom bleeder; 3) driver sider rear top bleeder; 4) driver side read bottom bleeder; 5) passenger side front; and 6) driver side front. Now and for whatever reason, ours are very sensitive to air. If you find your brakes fail or get spongey after bleeding, then you're sucking in air somewhere. Apparently, air molecules are smaller than break fluid molcus and you can be getting in air without seeing a break fluid leak. I had a problem with my breaks and had one @#$% of a time finding the problem. Turned out that one of my bleader valves needed replacing. Long story short, if you bleed your breaks in the correct manner and still have a problem after a few days, then its time to suspect your calipers, lines, etc. need replacing. Good luck.

 

At least one way air gets in is air pumping by the calipers. This is caused by rotor run-out which makes the calipers oscillate at a rapid rate when the brakes are not applied. The calipers will follow the uneven rotors and grab air, because it's easier to get air then to transfer the fluid back and forth with each osilation. If you have repeated problems with the pedal getting spongy, the rotors would be a good place to start checking. O-ring style calipers are less prone to this problem, but are not a fix-all for rotors with excessive runout. Leaking brake lines, calipers, hoses will not induce air into the system unless the master cylinder gets so low it introduces air.

 

That method works fine for me. I've used it on a lot of other vehicles too but after hearing all the bleeding horror stories here I thought I'd need a pressure bleeder. Not true. BTW I go around a second time just to be sure. Pretty simple.

 

OK here goes.....our '69 has been sitting for 10 years in our garage...Does it even pay to try and bleed the brakes or just go with a new master cylinder and new SS calipers. We did put on SS calipers about 15 years ago. I think my Dad tried to bleed the brakes about two years ago and the LR caliper was unable to get brake fluid to flow through..Sound good eh ?
Do I have to replace all brake lines too or are they useable..?
Thanks for a great thread...