Why is it so hard to bleed Legacy brakes ???

[professor]

This car is the hardest to bleed of all I have owned. WRX caliper bleed screws really suck... they are smaller than the original Legacy bleeders and the threads seal like crap, even after using two wraps of Teflon tape. I removed and cleaned the bleeders, still a pain in the butt. The threads are just sloppily cut and won't hold a seal at all, rendering my vacuum bleeder useless.

It just seems like when you pump the pedal, you don't get much of a fluid surge out of the bleeders.

I have YET to be able to bleed these brakes to satsfaction in a single session, and it takes at least twice as long at each corner as I'm used to

Is there a secret for Legacies only, of which I am unaware ??? My brakes work fine overall.

[vrg3]

Hmm, I've never had too much trouble... but it sounds like you know what you're doing.

One suggestion I might make is to pick up a set of speed bleeders. They have cold-rolled threads so the percent thread is higher, and they come with thread sealant on them. Remember that OEM bleeder threads aren't meant to seal at all no matter what. If there's a lot of air in the system, speed bleeders can supposedly cause trouble because of the force required to open the check valve, but in my experience the use of a vacuum bleeder makes that a non-issue.

Just to check -- When not vacuum bleeding, you're pressing the pedal slowly, opening the valve, letting it flow out, closing the valve, releasing the pedal slowly, waiting a few seconds, and repeating?

[professor]

Yeah, I think I'm fighting two devils - one, those threads refuse to seal at all. I know they aren't meant to, but usually a wrap or two of teflon tape and you can use vacuum bleeding very well, though I always finish the old-fashioned way as that loosens up and evacuates old fluid better.

two - the bleeder hole on the WRX brakes, in the bleed screw, is tiny. So small that I think small pieces of crap are plugging it up. the used calipers I bought were cosmetically great - on the outside. they seem a bit filthy on the inside.

the capacity of the master to pump fluid must be small - no great gush of fluid comes out when pumped, as with most brakes.

possible problem 3 is my 10 year old may not be pushing hard enough, all the time, although there should be little resistance with the screw loose.

perhaps when monkeying with all 4 calipers the amount of air is extreme. It might just take a while for it all to shake out - back to the master or to the calipers. still the pumping capacity of one stroke seems lousy

I may try the speed bleeders just out of curiosity

[vrg3]

If you think there might be gunk in the calipers, wouldn't it make sense to remove the calipers from the car and clean them out somehow? It'd suck for one of those pieces of gunk to score a piston wall or get stuck under the bleeder's seat...

If you're not already doing it, have your engine help your kid with the pedal -- run the engine so he/she gets some power assist from the brake booster.

[professor]

>>If you're not already doing it, have your engine help your kid with the pedal -- run the engine so he/she gets some power assist from the brake booster.

yeah I was thinking of doing that, except him knocking it into gear might be costly, especially without brakes. I suppose the ebrake and a couple of cinder blocks would hold it, though

[vrg3]

Ah, hm, yeah... if you're worried about that then maybe it's better not to. Unless you can wire the clutch pedal down or something.

Do you have another car and some hose? You could run the other car at idle and connect your Legacy's brake booster to the other car's manifold. Or, maybe you could adapt the pump from your vacuum bleeder if it's an appropriate type.

[evolutionmovement]

I haven't had any trouble either, but I don't use a vacuum bleeder. These damn systems can hold a LOT of air, though. I do a one-man job using a clear polyethylene (or propylene, I forget) tube that squeezes over the bleeder and submerges on the other end in a windshield washer bottle of old brake fluid. Everything's clear so it's easy to see bubbles in the hose by hanging out the open door. When I get to solid fluid, I have a bar I wedge between the pedal and seat to hold the brake pedal down while I tighten the bleeder back up.

Steve

[Richard]

You mean to tell us you know NOBODY who will give you a hand bleeding brakes? Even my mom, who has never driven a car in her life, was willing to help me bleed mine!

[professor]

>>>NOBODY who will give you a hand bleeding brakes? Even my mom, who has never driven a car in her life, was willing to help me bleed mine!


during the Patriots game, no

[evolutionmovement]

Why would I want someone to helpe me when I don't need it? Hell, I don't want people helping me generally even if I do need them. It's better that way as nobody likely would - I'm the asshole who helps everyone else but can only rarely find someone not suddenly MIA when I need something. None of the people who ever do help are unrelated women, I will add, as they have no character, just a hole between their legs.

Steve

[rightandtight]

you might try bleeding the ABS module a few times. there are some crazy bends in those pipes... assuming you have ABS

[professor]

Finally got it all squared away with an additional 4-wheel bleed, this time with my 7-year-old at the helm

The WRX bleeders just plain suck. They are smaller than the stock legacy bleeders both in thread size and wrench size. The threads fit loosely so throw away the vacuum bleeders, they won't work.

If you assume they are clogged you will be better off. Just unscrew them completely and let the line run free for a minute or two while you clean the bleeder with a stiff wire and air blast, then re-install and bleed normally. I had to take my front bleeders out three times to clear the holes. They are truly tiny, maybe half the size of the stock legacy bleed holes.

I chose to leave the rear brakes stock and fit WRX fronts, it seems to work very well to me, the WRX backs would be nice but it does not seem necessary for my driving style. Even though a wagon the front is very loaded with weight so the improvement there is striking. My fronts really sucked, they may have been original rotors (!)

[vrg3]

Cool.

I don't think the WRX rears are an upgrade over your stock rears.