Help! whole system brake bleed

[Jerrys95vette]

I would like to change out and replace all brake fluid and lines. I intend on replacing my hoses with steel braided ones all the way around. What is the best method for doing
this and ensuring a brake bleed that will work best? I have a hand-held brake pump but have never used to to breed brakes before.
Any advise?
Plus is DOT 4 better to use than DOT3? whats a good dependable brand?
Thanks to you all

 

[Wegone]

I use the recommended DOT3-4, Use a turkey baster to change the fluid in the master cylinder be sure to wipe out the black residue. Refill bleed the brakes per recommended method. You may not get it all changed as you would need a tech tool to cycle the ABS pump. After a few drives the fluid will discolor just change in master again may take a few times. I change whats in my master at every oil change.

 

[BRUTE86]

Bleeding Brakes

I would like to change out and replace all brake fluid and lines. I intend on replacing my hoses with steel braided ones all the way around. What is the best method for doing
this and ensuring a brake bleed that will work best? I have a hand-held brake pump but have never used to to breed brakes before.
Any advise?
Plus is DOT 4 better to use than DOT3? whats a good dependable brand?
Thanks to you all

Hi Jerry,
I wondered if you started addressing your brakes. What Wegone stated is correct, DOT4 is just an upgraded DOT3, work on the master cylinder first the way Wegone described it, then bleed the brakes.

Bleeding the brakes, the old fashion way is the best way [just my opinion]. I would use 3 people; the 'boss' would be in charge of loosening and tightening the brake nipple; one assistant sits in the car and pumps the brakes upon request; and the other assistant would keep topping up the master cylinder, and is very careful not to spill any fluid on the paintwork. If a spill happens, do not wipe it, just quickly pour water on to it.

You'll need a couple of sealed/new brake fluid bottles, an empty large plastic soda bottle 1/4 filled with water, and a yard of clear plastic hose, one end fitted over the brake nipple, and the other in the plastic bottle, with its end below water level at all times.

I'd removed the wheels, and start from the brake nipple furthest away from the master cylinder, in other words - passenger rear first, then driver rear, passenger front, and driver front. Get the assistant to start pumping the pedal and then hold it hard down. Open the first calliper's nipple and shut it when pedal goes right to the floor; you'll see the air bubbles, followed by the old fluid coming through. Repeat this method until the air bubbles and the old brake fluid stop coming through, and you see the new clean fluid coming through; shut the nipple, and top up where necessary.

Repeat this procedure with the other wheels. Don't lift the hose from the water in the bottle, and don't let the master cylinder go below 1/2 full.

Good luck,

 

[Jerrys95vette]

BRUTE86,
Thank you for the details. It’s been 30 years since I’ve bleed brakes and I can’t recall if I even did it correctly back then.
One question. I am going to replace the brake hoses, as I noticed cracks and chunks of rubber dry-rotting off of them when I replaced my back brake pads.
Will replacing the hoses change the dynamics of your instructions?

Thank you CAC friends…

Wegone, beautiful motor!!!!

 

[LLC5]

Be aware of the possibility of cutting and damaging the seal in an old master cylinder when you bleed the brakes by having someone push the pedal to the floor, I have seen it happen numerous times. The safest way is to draw the fluid out with a Vacula or similar device. Good luck with it.

 

[BRUTE86]

Bleeding brakes

BRUTE86,
Thank you for the details. It’s been 30 years since I’ve bleed brakes and I can’t recall if I even did it correctly back then.
One question. I am going to replace the brake hoses, as I noticed cracks and chunks of rubber dry-rotting off of them when I replaced my back brake pads.
Will replacing the hoses change the dynamics of your instructions?

Thank you CAC friends…

Wegone, beautiful motor!!!![/QUOTE
Hi Jerry,
No ! it won't affect the dynamics, I'm glad you mentioned the condition of your rubber brakes hoses, and that you're replacing them with 'braided steel' lines, that could save a reader from having a possible mishap.

Cheers,
Bert

 

[Hib Halverson]

First of all, what you read above about mixing water with brake fluid even in your bleeding container. Those who offer that advice have misguided ideas about brake service.

Also, I would avoid using a hand vacuum pump to bleed brakes. While that works in some cases, it also can cause more problems than it solves.

As for your task at hand....the first thing to do is change the brake hoses. When you go to buy a set of braided-stainless-steel-covered Teflon brake hoses, the best stuff meets FVMSS 108. These days, most of what's sold in sets for use on road vehicles meet that standard. The most recent set I acquired was for my 2012 and I got them from CAC sponsor Zip Products. Click here for C4 braided hoses.

In most cases, you'll need some metric flare nut wrenches to break the fittings loose from the chassis end of the hoses. I got my flare nut wrenches from the GearWrench people and they're reviewed here.

Connect each new hose to its calper, first, then connect it to the brake pipe on the chassis.

Once you have the hoses in place then flush the system and bleed.

I start by sucking the old brake fluid out of the master cylinder with a "turkey baster". Then I fill the reserviour with clean fluid.

Next, I install my pressure bleeder and pump it up to 25 PSI.

Then, I crack both fittings on the master cylinder for a half or second or so each.

Now, move onto the the brake calipers. I start at the farest one away from the master the RR. Now you need a container designed for bleeding brakes. I use a special brake bleeding "bottle" whch has the submerged hose built in and a wire loop I can hang on the suspension. The soda bottle "thing" works ok, but fill it with the brake fluid you sucked out of the master cylinder and not water. Submerge a clear plastic hose in the bottle, install your 10-mm bleeder wrench then open the bleeder. Watch the fluid flowing though the hose for bubbles. Bleed the RR caliper until the fluid "runs clean" and is bubble free. I usually rap the caliper at least once with a plastic hammer while the fitting is open.

Repeat that procedure at the LR, RF and finally the LF brake.

Now check pedal feel. With the brake booster bled down, it should be pretty firm. If it's spongy, repeat the bleeding procedure.

To flush the inside the modulator valve for the ABS you'll need to perform the Autobleed procedure discussed in the Service Manual. This requires a professional grade scan tester with chassis software. If you lack that, you'll need to take the car to a dealer or service facility with the right equipment to run Autobleed.

You can, also, bleed the base brake system, but not the ABS, manually by having an assistant pump the brakes while you bleed the master and calipers, however, most people misunderstand how to "foot bleed" the brakes. You don't pump the brakes rapidly and aggressively. You stroke the pedal slowly and firmly once or twice then hold moderate pressure while the bleeder fitting is opened. The fitting has to be closed while the pedal is still on the downstroke rather than when it bottoms. Wait five seconds between each stroke. Check the master cylinder level when you finish each caliper.

I usually pressure bleed because it's easier, more efficient and less prone to allowing air or contaminated fluid back into the system.

If you need more information on flushing/bleeding the brakes, see the Factory Service Manual.