I did a brake flush yesterday, by myself for the second time, on my 91 Civic LX (176k miles). I use the Mity-Vac system ( a hand-held vacuum pump, connecting to a small container to collect fluid, tubing, and adapters). It went much more quickly. One concern I have is that, while the kit has a well-fitting adapter for the front bleeder bolts, it does not have a good one for the rears. The front setup holds a vacuum really well as I bleed fluid. By contrast, on the rears, massive air bubbling occurs, and I have to continuously pump to maintain vacuum.
I think it's because the rear adapters fit so loosely that, when I draw a vacuum with the pump, it sucks air in at the adapters.
I am thinking of buying a set of those one-way (that is, check) bleeder valves that Pep Boys, for one, sells, to (1) maybe get a better fit from adapter to valve; and (2) minimize air introduction into the rear brake system.
Can anyone make other suggestions?
I want to stick with the Mity-Vac approach, as opposed to getting a friend to push the brake pedal while I bleed at each wheel. The Mity Vac system works really well on the front. I am optimistic that some brainiac here can help me getting the rears working better, or I'll stumble onto an improvement for the rears.
A few comments for the archives:
-- I used a 32 oz ( = two pints) container of Valvoline "exceeds DOT 3 and 4 requirements" brake fluid for the flush. I had a second container ready, in case I found a lot of dirt etc. in the fluid I bled. I did not. It seemed pretty dirt free.
-- About 1.8 years and 22k miles have elapsed since the last flush. The Owner's Manual recommended interval is 2 years and 30k miles. I see a lot of folks here do a brake system flush once a year. I was thinking of switching to a one-year interval, but think I'll stick with two years using the more expensive, supposedly more moisture resistant Valvoline brake fluid. I live in a low humidity part of the country, to boot.
-- The brake pedal travel before and after the flush still seems a little large. I'm thinking it's because in fact I am not getting all the air out of the system, and if any part is to blame, its the rear bleeder bolt/adapter set-up I'm using. Or possibly it's the fact that yesterday just before the flush I disassembled, cleaned, lubed, and inspected, then re-installed the rear brake shoe assemblies, and so they weren't quite seated right.
-- I do not see symptoms of a leaky master cylinder (e.g. the brake pedal does not keep going down after I first hit what seems "bottom").