Pressure bleeders can be used empty

[noid]

Protip for those looking to make their brake bleeding experience incrementally more enjoyable and not in the know: pressure bleeders can be used completely empty.

Almost all pressure bleeders are advertised as needing brake fluid added to them and then pumped to pressure.

This only serves to prevent the cars reservoir from going empty. If you don't bleed out all of the fluid in the reservoir then there is no concern whatsoever.

The benefit is a completely mess free experience; no dripping from the cap, no fluid to dispose of in the pressure bleeder, no excess fluid in the bleeder lines, etc.

Just fill up car res to full, connect cap, pump to 10 PSI, connect catch cup to bleeder ******, open until no more bubbles, close and done. No mess no fuss.

 

[Kps]

Wonderful!

 

[matt_i]

That's s good idea...a corollary might be to top-up the master cylinder reservoir right before bleeding. Like right to the top where it would be normally over-filled to give yourself the best chance of not going dry.

The "driver" for the bleeder could also be air-compressor based with a couple of stages of air pressure regulation too....just seal a fitting to a cap, fully cured epoxy will work for 10psi and off you go.

 

[noid]

That's s good idea...a corollary might be to top-up the master cylinder reservoir right before bleeding. Like right to the top where it would be normally over-filled to give yourself the best chance of not going dry.

The "driver" for the bleeder could also be air-compressor based with a couple of stages of air pressure regulation too....just seal a fitting to a cap, fully cured epoxy will work for 10psi and off you go.

No need for an air compressor, 10 psi takes only but a few pumps and will hold for the duration of the bleeding (within 2-3 psi).

There is no risk in pumping to 15-20 psi if you want an even faster experience.

Like you noted, filling the res to the very top gives a great starting point.

 

[Chevy-SS]

LOL, great tip! I've been using pressure bleeders for years and never thought of doing it that way, but it makes perfect sense. I had one dry-rotted hose (from bleeder to M/C) blow up on me, that was a mess. I use lots of fluid when bleeding, usually flushing the system pretty good, so your method would not typically work for me, but it's good for those quick bleeds!!! Thanks

 

[Wamsutta]

There is no risk in pumping to 15-20 psi if you want an even faster experience.

Motive Products Power Bleeder says to check service manual for recommended pressure - which I haven't done yet. The information is probably buried in there somewhere and I'm not looking forward to trying to find it.

 

[mikegt4]

Many years ago I made some brake fluid reservoir cap adapters to allow direct hookup of compressed air controlled by a small 0-30 psi regulator. It worked but constantly having to de-pressurize the MC and refill fluid got old pretty quick. Then I made up a pressure bleeder reservoir out of PVC pipe fittings that would hold a small size can (12 oz?) commonly used for brake fluid inside a pressurized chamber. The convenience of not having to constantly check/fill the master cylinder was great but was offset by the time, effort and mess of cleaning it and the hoses after each use.

Recently I was about to flushed the brake fluid in all my vehicles as part of normal maintenance (make that deferred maintenance) and decided to look at Motive and similar bleeders but the old problem of cleaning it after each use (2-3 years between each use) reared it's ugly head again. I ended up going full circle back to reservoir cap adapters and a small regulator to control air pressure. Instead of making my own adapters out of junkyard sourced caps I bought some commercial level adapters made by Power Probe which worked great. They are superbly made out of aluminum, a refreshing change from molded plastic, and will last a lifetime. For the air supply I got some quick release end fittings to match the male fitting supplied with the adapter, a common Milton size, at my local Rural King.

https://www.carcertifiedtools.com/collections/adapters?page=2

 

[noid]

Motive Products Power Bleeder says to check service manual for recommended pressure - which I haven't done yet. The information is probably buried in there somewhere and I'm not looking forward to trying to find it.

Only if above 20 PSI.

"6. Tighten pump cap. Pressurize Power Bleeder to level recommended in vehicle service manual. Do not exceed 20 psi unless specified by your service manual. Higher pressures may damage your vehicle's reservoir and could result in serious injury."

https://www.motiveproducts.com/pages/power-bleeder-instructions

Many years ago I made some brake fluid reservoir cap adapters to allow direct hookup of compressed air controlled by a small 0-30 psi regulator. It worked but constantly having to de-pressurize the MC and refill fluid got old pretty quick. Then I made up a pressure bleeder reservoir out of PVC pipe fittings that would hold a small size can (12 oz?) commonly used for brake fluid inside a pressurized chamber. The convenience of not having to constantly check/fill the master cylinder was great but was offset by the time, effort and mess of cleaning it and the hoses after each use.

Recently I was about to flushed the brake fluid in all my vehicles as part of normal maintenance (make that deferred maintenance) and decided to look at Motive and similar bleeders but the old problem of cleaning it after each use (2-3 years between each use) reared it's ugly head again. I ended up going full circle back to reservoir cap adapters and a small regulator to control air pressure. Instead of making my own adapters out of junkyard sourced caps I bought some commercial level adapters made by Power Probe which worked great. They are superbly made out of aluminum, a refreshing change from molded plastic, and will last a lifetime. For the air supply I got some quick release end fittings to match the male fitting supplied with the adapter, a common Milton size, at my local Rural King.

https://www.carcertifiedtools.com/collections/adapters?page=2

Using caps from the junk yard is actually a really cool idea. Should be as easy as barbing and sealing.

But I agree, the aluminum adapters are awesome for frequent use.

The nice thing about the bigger pressure bleeders (like the Motive) is that the larger container can hold a greater volume of air and therefore can sustain pressure for longer; no need for compressed air.

At 10PSI the cap is normally easy enough to unscrew, so releasing pressure and topping up as needed hasn't posed any significant delay.

 

[Ralf11]

I've always done that.


BTW, anybody put Speed Bleeders on their car? They have a one way valve in them - dunno if it is easier than using a pressure bleeder or not...

 

[Wamsutta]

Only if above 20 PSI.

"6. Tighten pump cap. Pressurize Power Bleeder to level recommended in vehicle service manual. Do not exceed 20 psi unless specified by your service manual. Higher pressures may damage your vehicle's reservoir and could result in serious injury."

https://www.motiveproducts.com/pages/power-bleeder-instructions

Thank You. I appreciate that. Saves me a lot of trouble.

 

[Milton Shaw]

The old Ammco bleeder I used years ago had a diaphragm in it that would shut the flow off when you were out of fluid. The diaphragm separated the fluid from the air so it wouldn't do anything without fluid in it. So I don't know if using other brands dry would work, I know it would not work on the old Ammco bleeders.

 

[JJ13]

That's s good idea...a corollary might be to top-up the master cylinder reservoir right before bleeding. Like right to the top where it would be normally over-filled to give yourself the best chance of not going dry.

The "driver" for the bleeder could also be air-compressor based with a couple of stages of air pressure regulation too....just seal a fitting to a cap, fully cured epoxy will work for 10psi and off you go.

You're right that you want to slightly overfill just before bleeding. When flushing the brakes I had to refill the reservoir for each line. I made a pressure bleeder for about $25 using the cheapest garden pressure sprayer ($9-11), a pressure gauge, and a few brass fittings. I reused an extra reservoir cap that came on a used booster that still had the master cylinder attached. It worked well for a while but I recently threw it away as I couldn't get the DIY cap to seal. Cleaning up 2/3 quart of brake fluid that squirted out of my DIY cap was NO FUN!

I bought a Motive with aluminum cap for about $65 and will never again fill the pressure vessel with fluid. The shorter Motive bottle takes 50-60 pumps to get up to 15 psi where my DIY garden sprayer bottle had a longer piston stroke and was faster to use. My recommendation would be to buy the Motive cap that fits your car/s and make your own pressure sprayer bottle or use an air compressor if you trust you can get reliable low pressure from your regulator.

 

[JJ13]

I've always done that.


BTW, anybody put Speed Bleeders on their car? They have a one way valve in them - dunno if it is easier than using a pressure bleeder or not...

I used them 20 years ago. The problem with Speed Bleeders is the thread sealant wears out. About the fourth time I bled my brakes air was able to get back in through the threads as the pedal was released. They sell extra thread sealant to refresh them but I'd rather have a pressure bleeder. With pressure you're working at the brake watching the fluid come out. With Speed Bleeders you're stuck in the car wondering when you've flushed all the old fluid out and you cannot easily see how full the reservoir is.

 

[JJ13]

Motive Products Power Bleeder says to check service manual for recommended pressure - which I haven't done yet. The information is probably buried in there somewhere and I'm not looking forward to trying to find it.

Cars without ABS require less pressure. My previous car didn't have it and it bled with less pressure, the new car (same model but newer with ABS) required 15 psi before I noticed any real flow at the caliper. I also jumped the diagnostic connector so I could lightly apply the brake, turn on the key, and put ABS into diagnostic mode to make sure all the fluid was flushed.

 

[noid]

Cars without ABS require less pressure. My previous car didn't have it and it bled with less pressure, the new car (same model but newer with ABS) required 15 psi before I noticed any real flow at the caliper. I also jumped the diagnostic connector so I could lightly apply the brake, turn on the key, and put ABS into diagnostic mode to make sure all the fluid was flushed.

Some cars you cant bleed properly at all without software. The BMW X5 for example requires the use of INPA to go through a ABS actuation process.

 

[Chevy-SS]

Some cars you cant bleed properly at all without software. The BMW X5 for example requires the use of INPA to go through a ABS actuation process.

Is there a list available anywhere showing the vehicles that require use of proprietary software to bleed brakes??

 

[noid]

Is there a list available anywhere showing the vehicles that require use of proprietary software to bleed brakes??

I don't believe so, but the cheapest bi-directional reader that can do some (most?) modern cars is the Autel Maxicheck pro (~$200).