Bleeding brakes

[dburgjohn]

I am about to replace my rubber brake lines with stainless. When I bleed the brakes do I need to start at the ASR unit or can I just do each caliper as I change the hoses?

[c4cruiser]

Bleed each caliper after replacing all 4 hoses. Now would be a good time to do a flush of all the fluid. Takes about a quart for a complete flush. The ABS/ASR system is not normally flushed by the regular bleed procedures. You would need a Tech-1 with the Brake System Cartridge in order to operate the system and move fluid thru it.

Bleed the calipers in this sequence (from the GM Service Manual):
Right Rear
Left Rear
Right Front
Left Front

Use a good DOT3 or DOT4 fluid. I use Castrol LMA in my 92 for general street use and in my 87 autocross car, I use the Ford High Performance fluid.

[Moonunit 451]

Originally Posted by c4cruiser

Bleed each caliper after replacing all 4 hoses. Now would be a good time to do a flush of all the fluid. Takes about a quart for a complete flush. The ABS/ASR system is not normally flushed by the regular bleed procedures. You would need a Tech-1 with the Brake System Cartridge in order to operate the system and move fluid thru it.

Bleed the calipers in this sequence (from the GM Service Manual):
Right Rear
Left Rear
Right Front
Left Front

Use a good DOT3 or DOT4 fluid. I use Castrol LMA in my 92 for general street use and in my 87 autocross car, I use the Ford High Performance fluid.

Agreed, but what is a "Tech-1 with the Brake System Cartridge in order to operate the system and move fluid thru it."

Just did the J55 upgrade last Saturday with braided lines, took FOREVER to bleed. The procedure was even more complicated according to my friend. Do not depress the brake pedal more than 75% and count to 15 on the "up" stroke. I just followed instructions But the result was FANTASTIC

[c4cruiser]

A Tech-1 is the model name of the diagnostic scanner device that a GM service tech plugs into the ALDL connector to read any codes stored in the car's ECM (engine)or CCM (body) computer. The Brake System Cartridge plugs into the Tech-1 so error codes can be read from the Electronic Brake Control Module (ABS computer). Tech-1's cost around a grand used when you find them but there are a lot of good diagnostic scanners abvailable to help troubleshoot problems when a warning light such as the "Service Engine Soon" light comes on in the DIC.
The Tech-1 with the module installed can "run" the ABS pump so that fluid passes from the master cylinder to the ABS/ASR system. It isn't really necessary to do this as the new fluid will eventually flush itself thru the system. After a few weeks, you might find the fluid in the MC resevoir will become dark. Simply suck that fluid out with a turkey baster and replace with new fluid.

BTW, if you want to make brake bleeding a one-person job that takes only a few minutes to do, get a set of Speed Bleeders and install them on the calipers. They have a spring loaded ball in them that opens the bleeder when you depress the pedal and snaps back as you release the pedal. Inexpensive and a great way to keep fresh fluid in the system. https://www.speedbleeder.com/ Corvettes use the SB1010 bleeder.

[Moonunit 451]

Thanks C4, great info

[dburgjohn]

Originally Posted by c4cruiser

get a set of Speed Bleeders and install them on the calipers.

I bought a set when I got the new lines. They sure do make a difference. It is day three of this project as I only get a little time each day. It does not help that I keep stopping to clean and polish the surrounding parts. My wife says I have a real problem about doing that but I can't help myself.

[WhalePirot]

I change the brake and clutch fluids when they get dark, due to water absorbtion. I try not to baste the turkey with the same baster I used on the car, tho.

ONE poor man can snug a piece of hose over the bleeding screw on each caliper, in the aforementioned order, drop the other end into a can with some used brake fluid in it, 'crack' the bleeder open and pump the brake pedal slowly. The hose eliminates sucking air back into the caliper, blocked by that old fluid covering the 'other' end of your hose. If the hose is translucent, you will know when clean, dry brake fluid replaces the 'wet' dark fluid.

Ensure that you don't totally drain the master cylinder, spill brake fluid on cherished paint OR remove the hose before retightening the bleeder.

[dburgjohn]

I use a vacum pump and speed bleeders together

[tlong]

I did the job with a Power Bleeder from Motive. It's a garden sprayer filled with your new fluid choice that pumps up to 20 lbs psi and attaches over the fluid resovoir (sp).
You just open the bleeders in farthest away sequence and wait for the new fluid to come out. It's as easy as it gets. $50. Not 1 drop spilled.

Then drive for a month and do it again because you can't get into the ABS with it.