Bleeding a clutch line with engine vacuum

Last weekend I drove by a Mazda Protoge with it's hood up in a parking lot. 30 minutes later it is still there with 3 people standing around it looking befuddled. I have some Mazda parts less than a mile away so I stop to see if they need help. The rubber line from the clutch master cylinder to the slave cylinder had broken. These guys had made a good repair using a piece of brass tubing inside the rubber hose secured with hose clamps. They were having a hard time bleeding the line. My mighty-vac vacuum pump is loaned out so I could not loan that to them. As I drove off I had an idea. If I put a hose on the bleeder and put the other end on a vacuum port on the intake it should bleed. I stopped at the hardware picked up 4' of clear vinyl tubing. I went back and explained what I had in mind. We hooked up the tubing, fired up the engine and the fluid started flowing. In under a minute the bubbles and nasty looking fluid were gone. It worked very well. I might start bleeding my brakes this way. Are there any disadvantages to this method?

Your screen name should be pilotMacGyver.
Nice thinking outside the bun.

Why isn't this more common? Especially with one of the in-line resevoirs (like from my broken Mity-vac,) so you don't suck flud into the engine. I may have to try this.

Brake fluid eats a lot of things you wouldn't expect it to, might not play well with the intake valve stem seals.

Kenny_McCormic wrote: Brake fluid eats a lot of things you wouldn't expect it to, might not play well with the intake valve stem seals.

That's why I think an in-line resevoir would be critical.

Tyler H wrote: Why isn't this more common? Especially with one of the in-line resevoirs (like from my broken Mity-vac,) so you don't suck flud into the engine. I may have to try this.

exactly... my HF pump was a POS and died quickly... but still have that inline bottle... been using it as a large 1 man bleeder bottle... but I may have to try it out like this...

Kenny_McCormic wrote: Brake fluid eats a lot of things you wouldn't expect it to, might not play well with the intake valve stem seals.

I did tell the guys that I would run some carburetor cleaner through the same vacuum port, just in case something didn't like brake fluid.

I have no idea how I remember this, but some guy patented this idea many years ago. I don't ever remember seeing a commercially available unit for sale though.

Engine Vacuum Brake Bleeder