Chevrolet Cruze Forums banner
1 - 2 of 2 Posts

·
Banned
Joined
·
10,296 Posts
Vacuum bleeding works perfectly fine as long as your master brake reservoir stays full with fresh brake fluid, but wasting a lot more fluid this way because mixing old with the new. With pedal pushing, that master cylinder piston with that rubber ring on it will see places it never saw before and may wreck that seal after a vehicle becomes a couple of year old.

Use to be able to buy new rubber for a couple of bucks, now have to buy a new master cylinder. Had ABS for many years. what year is this? Hmmm, least 35 years, could hot wire the ABS pump for very rapid and clean bleeding, just did this on my 88 Supra, had to rebuild all four calipers due to old age, got buy with four bucks a caliper with all new rubber. ABS had to be drained to do this and leaves air in the pump.

Dealer drained it dry on my Cruze when the rear calipers had to be replaced, would ratchet anymore, claims he pressure bled it, can believe this, left brake fluid all over the engine, what a mess to clean up. Shop manual explicitly states must use a GM Tech II scanner with an ABS module to activate the pump, left me with a pedal that when clear to the floor. Can't argue with these guys.

Since he wouldn't loan his scanner to me, only choice I had was to vacuum bleed, take the car for a short ride, 0 to abut 8 mph, shut it down and do this 3 or 4 times to run the pump, then vacuum bleed again. Had to repeat this sequence four time until I finally got a full pedal. This is practically true on all vehicles since our congress made ABS law, just have that tiny cube with a slot car pump motor on it with no access to that motor.

Manual also states if you do have the scanner, only run that motor for short periods of time or you will burn it up! One thing I really noticed, that ABS only pulses about one pulse per second, use to be 10 pulses per second on all of them, next to worthless, but is the law! Can fan that brake pedal a lot quicker than this.

That Foxwell NT510 for around a 175 bucks claims to activate that pump plus even show all ABS codes. Looking into this.

Dealer didn't even know you have to work the parking brake with rear disc calipers, if you do have an excessive pad or shoe clearance, can quickly pump up the pedal, but if you do have air in the system, can't pump all day and that pedal will be low.

BMW recommends a complete ABS flush every year, I from experience feel once every 2-3 years is enough. Today, an ongoing debate if Dot 3 or 4 is better, good question, both have downfalls.
 

·
Banned
Joined
·
10,296 Posts
Took a one pint Mason jar with a handle on it, years ago, and punched two !/4" holes in the lid, soldering two !/4" diameter inch long brass tubes only about an eighth of an inch below the lid, Use this with a hand operated vacuum pump.

You can remove a bleeder without losing any fluid and coat the threads with Permatex non-hardening gasket maker, this way when you pump, will not be putting air through the loose threads.

That Permatex also helps to reduce corrosion so the next time in a road salt area, can remove the bleeders without breaking them off.

Sequence is RR, LF, LR, RR front, just back up the car on my oil changing ramps, have no problem with the front, can turn the steering wheel left or right and reach the bleeders with the tires on the floor.

As long as the reservoir is full, won't have any problems with air getting in the ABS, and have the knowledge, the job was done right.

Hand vacuum pumps became popular in the late 60's, stay away from plastic. Ha, first one I got was plastic, got a little gas in it, that was the end of that, got a metal one shortly after with replaceable O'rings, still good after some odd 40 years.

Before vacuum pumps, only way to test was to suck with your mouth, and if gas, yuk and double yuk, with a clear plastic line, can see when the fluid comes out clean. Around here, Fleet Farm sells it by the foot. Also use a clean funnel, so the brake fluid goes in the reservoir and not all over the place, think they call this common sense.
 
1 - 2 of 2 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top