Bleeding brakes with a 12v suction transfer pump

This probably doesn't have enough pressure to suck out brake fluid.

loonieryan wrote: ↑ I usually bleed brakes with a handheld vacuum pump but it's tedious and I thought why not use one of these 12v suction fluid transfer pumps: https://www.amazon.ca/dp/B07WNTZB79/ref ... M1Q1BSVSEA

I've already got one that I had used for something else so don't have to buy it. Any reason why this wouldn't work it? I figure I could just connect it to the bleeder nozzle, turn it on, loosen the valve and let fluid out.

I think the positive pressure bleeders are better. I just use my wife or kids to pump the brake pedal.

board123 wrote: ↑ This probably doesn't have enough pressure to suck out brake fluid.

How much suction do you think you need when bleeding brakes? You don't need much, i have a feeling this would work just fine.

mxthor3 wrote: ↑ How much suction do you think you need when bleeding brakes? You don't need much, i have a feeling this would work just fine.

I don't know, but I feel like the brake pedal applies a lot of pressure to the fluid. Possibly more pressure than what you can get from a small pump like this.

mxthor3 wrote: ↑ How much suction do you think you need when bleeding brakes? You don't need much, i have a feeling this would work just fine.

once you crack open them bleeder valves the weight of the brake fluid and gravity is already doing the work for you. The suction tool is nice if you are pressed for time or have jobs lined up one after another.
for me I have all the time in the world and not going to spend money when gravity is free.

board123 wrote: ↑ I don't know, but I feel like the brake pedal applies a lot of pressure to the fluid. Possibly more pressure than what you can get from a small pump like this.

There is a ton of force when the engine is on and you have vacuum boost assist. There is still a fair bit when it's off and just your foot on the pedal. But with the bleeder open you don't need much force to push it out if the reservoir cap is open.

I used that before for sucking out oil from an engine. Takes. For. Ever.

If you are planning to stick the one end on the bleeder, I suppose it might work. Would need to use a clamp to secure to the bleeder. Just need to figure out which force is greater, your dinky yellow pump or master brake cylinder negative vaccum. You will probably end up going inside the car and start manually pumping which will end up creating mess everywhere when clamp explodes from too much force and yellow pump that can't handle pumping faster then your foot can.

Just use a one-man bleeder kit with a one-way valve. Faster than using a hand pump (which does work well under some circumstances though). The 12v pump would probably be about the same.

The way I usually do it is pump the pedal first until it's firm to build up pressure in the lines. This is usually enough by itself to get fluid running out as soon as the bleeder valve is opened, so this electric transfer pump shouldn't even need to work that hard to get the fluid out. And of course, I would make sure it's securely attached to the valve.

I've never used a one-man bleeder kit, so will have to look that up. I've used the hand pump (this one from Princess Auto) and I find it takes a lot of pumping of the pump itself to build up vacuum and tends to leak air even though I've used the included adapters to get a secure fit.

cristianosham wrote: ↑ once you crack open them bleeder valves the weight of the brake fluid and gravity is already doing the work for you.

That's exactly what I do.

No need for pumps, bleeder kits, pumping the pedal, etc...

Goes pretty quick if all 4 bleeder are open at the same time. Just make sure the reservoir stays full.

I get my 8 year old kid to pump.

cristianosham wrote: ↑ once you crack open them bleeder valves the weight of the brake fluid and gravity is already doing the work for you. The suction tool is nice if you are pressed for time or have jobs lined up one after another.
for me I have all the time in the world and not going to spend money when gravity is free.

Sitting around waiting for the brakes to bleed themselves. That's a new one.

mxthor3 wrote: ↑ Sitting around waiting for the brakes to bleed themselves. That's a new one.

I got all the time in the world especially during covid. so get a drain pan or four if you do not have all the time in the world, crack open one or all four bleeders. make sure the brake fluid reservoir is always full and wait until the fluid at the bleeders are clean and close them up after. I don't think that is something new and don't go pumping the brakes with the bleeders open.

I've never thought of setting up brake bleeding to go faster. The most labour for the job is the set-up / clean-up and the biggest risk is getting air in the abs modulator so I don't mind moving slowly on this job. I only do it once every five years on my vehicles so time efficiency isn't a huge matter.

I use this Mityvac on Amazon

engineered wrote: ↑ I think the positive pressure bleeders are better. I just use my wife or kids to pump the brake pedal.

I literally thought this was the only way to do it. My spouse makes me come out every time. I'm not always positive about it though.

zeddy wrote: ↑ I literally thought this was the only way to do it. My spouse makes me come out every time. I'm not always positive about it though.

It's the best method IMO (pressure rather than suction) but you don't really need a second person as you can either get cheaply available speed bleeder valves (so you can do it solo); or get a pressure bleeder like the Motive tool.

I use my Mityvac MV8500. I won't swear by it but it's simple enough to use and it works. Brakes always feel amazingly tight after a fluid change. If I was to go all out for equipment, I would get a positive pressure kit but I do this so infrequently, that I don't mind turning to my Mityvac.