Brake bleeding

[Reg]

Has anybody tried creating a Heath Robinson DIY vacuum pump for brake bleeding, I have been thinking about how it could be done:

1. Connect engine vacuum from inlet manifold to a container with a shut off valve, add maybe a S111 vac reservoir.
   
2. Use a vac pump such as a RR cruise control pump, reservoir etc.
   
3. Use diesel engine vac pump coupled to a small electric motor.
   
4. Use a Series alternator and vac and drive it off a motor using the existing pulley.
   

I know you con buy hand Vac pump kits and some fancy industrial units but Im thinking of using bits out of the "box in the shed" kind of things.

[Dave W]

I'm not sure what/if there is any benefit to using vacuum over pressure, I use a pressure bleeder (Gunsons in my case) and have never had a problem bleeding the brakes with it.

The reason I mention this is I think it would be easier to make a pressure bleeder than it is to make a vacuum bleeder. A spare wheel aired down to 20psi makes a reliable and stable "power source" for the system and you can use it either with or without a fluid reservoir. Beyond that, all you need is a few bits of pipe and a spare reservoir cap.

Having a fluid reservoir is more complicated but saves a bit of time as you don't have to worry about the amount of fluid you're using, it also makes it a doddle to do a complete fluid change. If you modify a cap off a bottle of brake fluid you can use the bottle as a reservoir although you'd want to do some checks with air only first to make sure it's sealed and won't explode on you !