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Air in brake system - '91 Loyale

Hello all,

'91 Loyale 4x4 wagon

I just did a bunch of front-end work that required removing the brake calipers. After hooking everything back up, I keep getting air in the brake system at both calipers when I bleed the front brakes. I bleed them until there's no air, then come back a couple of minutes later and there's air again.

It seems to me air must be getting in at the calipers because the reservoir has never run dry. The only things I can think of are: 1) I didn't replace the sealing washers on the banjo bolts, as suggested by the shop manual; 2) There are two sealing washers per banjo bolt. I put one on either side of the banjo bolt assuming that's how it was before, but I don't remember for sure. Maybe one of these is allowing air to get in?

Any thoughts out there? Thanks in advance.

Reply to
Rick
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Sounds right with the washers (one washer on either side of the banjo bolt) - plus, the system would tend to leak fluid out rather than let in air (since the reservoir is the highest point in the system) - as long as the washers weren't scored (were still smooth) they should be fine - when you removed the calipers, you may have gotten air into the master cylinder, which can be a serious pain to bleed (never done it on a Subaru, but on many cars you need to remove the master cylinder and bleed it on the bench to get all the air out.)

Reply to
David & Caroline

Hello again,

Ok, here's the deal. I bled all four wheels diagonally and got air at all four wheels, twice. I haven't bled the master cylinder yet because the bolts on the brake lines are a major PITA to get loose and, more importantly, the more I work on this, the more convinced I am that air is getting in.

The thing that has me thinking this is that I have bled enough air out of the system over the last three days to fill the entire system at least once, no kidding, not to mention the quart of fluid I have put through it. I can't imagine that much air could be trapped in there. My understanding of hydraulic systems is that air can get trapped and compromise the system, but I have a continuous supply of air bleeding out. At some point the air has to stop coming out if air is not getting in, even if an air pocket remains trapped in the system.

So, I'm thinking that maybe it's just a strange coincidence and the master cylinder has a leak. Any thoughts or, better yet, does anyone know how to test this? I'm curious to know what other people think.

Thanks - Rick

Reply to
Rick

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