Vacuum bleed brakes?

[96-2D-Hoe]

Is using a vacuum more effective, or just easier than manually bleeding these PIA brake systems?

I have a vacuum pump and was thinking of making myself up a jar so I could use it to bleed the brakes. I've done it using the pipe in a jar method on my own and can change the fluid pretty easily.

Also need to bleed my ABS. I've tried the driving to a gravel road slamming on the brakes and then going home and bleeding method to excess, and it definitely helps, but it doesn't seem to clear everything.

I've asked at a few places that have the correct scan tool, I can't remember which one that is right now, and they didn't want to do it quoting liability. Which leaves me the stealership. I could try look harder I guess.

 

[drakon543]

vacuum bled brakes are easier as you can do it completely by yourself instead of one on the pedal one at the bleeder. or the method im generally stuck with using a stick and the front of the seat. ive just been too stubborn to get one myself.

 

[96-2D-Hoe]

I normally do it on my own with 3' plastic hose with one end in a jar with a little fluid at the bottom. It will also gravity 'flush' if you can wait long enough

I'm hoping for a miracle that doesn't include the scan tool I guess.

 

[east302]

I had a shop do the ABS procedure (followed by a normal bleed at all four corners) for around $80 a couple of years ago. I think he had a SnapOn scanner, but I had to tell them what I wanted done.

I gathered that it was not a common request, but they had no issue doing it.

I did swap the master cylinder to a next generation one and used a Motive pressure bleeder on it since it has the threaded reservoir cap. It makes it so much easier, I’ll never go back to the manual method, that’s for sure.


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[96-2D-Hoe]

I've asked at a couple places, they don't want to do it. Was tempted to swap mine out with the pickup MC that was supposed to give a solid pedal and not soccer mom, but just went with a regular one. Was a real PIA as I got a couple bad ones, or I broke them, not sure which. The one I have now has bad seals and leaks at the bottom of the reservoir when I take the lid off. I wasn't going to change it again so I lived with it. I spent literally hours/days bleeding the brakes.

What MC did you go with? Any pedal improvement?

 

[Rocket Man]

I highly recommend the Motive pressure bleeder. Pressure instead of vacuum. I tried the vacuum ones and they’re a pia. It’s not the cheapest but once you’ve used one you’ll never use anything else. Even automatically refills the mc. No compressor needed either.

 

[east302]

I've asked at a couple places, they don't want to do it. Was tempted to swap mine out with the pickup MC that was supposed to give a solid pedal and not soccer mom, but just went with a regular one. Was a real PIA as I got a couple bad ones, or I broke them, not sure which. The one I have now has bad seals and leaks at the bottom of the reservoir when I take the lid off. I wasn't going to change it again so I lived with it. I spent literally hours/days bleeding the brakes.

What MC did you go with? Any pedal improvement?

Pedal height is much better, especially with the drums adjusted tight. I have two 98s, one is a Z71 truck and the other a two door Tahoe, both with the JB5 drums. The truck pedal with the stock MC damn near goes to the floor by comparison. I’ll swap it as well the next time I get into it.

I think I spent maybe fifteen minutes bleeding it and most of that was just setting up the pressure vessel. It’s just no comparison to the two-person method.

Here’s what I used. I forget the part number for the reducer in the brake line, but it was from autozone.

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[SnowDrifter]

I vac flush mine. Lot easier to get enough fluid through the system than up down up down up down up down up down up down up WAIT SHIT **** NOT YET.

Always finish with a pedal pump or two though. Vacuum bleeding inevitably sucks air past the threads on the bleeder

 

[96-2D-Hoe]

Thanks for replies

FYI While I was trying to bleed the air out of my ABS, i found every time I bled the fluid after setting it off there would be a bunch of nasty black crap that came out of it. Also puts a bunch a nasty crap back in your reservoir. I did that a LOT of times and there was always something, otherwise the fluid looked like new as I had put so much through it. That ABS flush with a scan tool should probably be part of a regular service routine.

You really don't need two people just to change the fluid. Take the lid off the master cylinder reservoir first, change that fluid, and put the lid back on loosely, don't let it run dry, and put plenty towels/rags all around it, especially toward the back/brake booster. Hook a hose to the bleed screw and loop it upwards, I have a hole in a pint jar that holds the hose tight, and I put the jar on the tire with a little fluid so the bottom of the hose is under it. Open the bleed screw and the fluid forces the air out, then back it right up to just a crack open, less is better so you get some pedal resistance. Then you go in the truck and push the pedal, slowly and gently, not quite all the way to the floor, use a block to stop the pedal going all the way down if you're a blockhead (like me) or you will screw the MC up, wait 10 secs before pushing the pedal again. Flushes no problem. As for bleeding, I have got some air out, but never enough.

I looked at the Motive earlier as I've seen a few people recommend it. They have a kit for the standard GM lid too I think. But it didn't have great reviews. At $60 ish it's on the threshold of whether I screw around and make my own for $30 that I can hook to an air compressor or just suck it up

Must admit, when I first got this truck I tried 2 person flushing the brake fluid with a buddy in the truck that didn't know what he was doing, and somehow I got air in it. It was only off a little, still way better pedal than I have now. Even the stealership took couple tries to get it right, and that was only because I knew how good it should be. When it's right, you really don't need anything more. (Have been looking at MC upgrade posts).

Spent more on the truck than I wanted to lately, but I have wanted to get it back in very good shape. Looking at brakes now. I guess it keeps me busy and off the streets.

 

[96-2D-Hoe]

I changed all my bleeds screw as they weren't in good shape and put them back in with a little ptfe tape. Stops that pretty much, but doesn't last very long. Good advice. Thanks.