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Bleeding dual circuit brakes?

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RickB

RickB

Yoda
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The pedal still feels a bit soft after bleeding yesterday.
Actually it's great sometimes and a bit soft other times.
I am thinking my front circuit is great but my back circuit has air in it.

Is there anything special I have to do to get this bled properly? In particular what to do about it when you open up the bleeder & press on the pedal the front brakes engage & the pedal is firm? It doesn't seem I'm getting much action towards the back. It's been a long time since I've done this.
Thanks!
 
Hiya Rick,

I had a really hard time bleeding the brakes on the Midget until I bought a hand pump (see for example the Mityvac ). I find it much easier, and can now bleed the brakes without an assistant.

Good luck hunting down your air bubbles!
 
Rick, is the hose at the rear in good shape? A hose that is deteriorated can cause restricted flow, making it hard to bleed the brakes. Not to mention severely imparing their overall operation.
Jeff
 
Thanks guys, yes the hoses are all great. It's really just that I don't have the right size wrench for opening the bleeder & they don't sell it at the parts store and I had to use needle nose locking pliers and etc etc etc.
Seems better now that I've done it the third time.
 
Funny, I thought I tried a 1/4 inch and it was too big.
Also tried 6mm & it was too small while 7mm was too big.
Sounds like a 1/4 doesn't it?
 
I've had great results with a vacuum device called a Vacula you need a air compressor to "power" or drive it but all you have to do is attach it to the bleeder port open it and it will suck all the air/brake fluid for you I 've used to suck the old fluid out of the master cylinders, transmissions any thing you need to remove fluid from I still will bleed the old fashion way just to check for air once I have clean fluid coming out but it sure saves alot of time bleeding out new or old systems
 
In the category of "no good idea ever goes unpunished" I decided I'd go ahead and replace the fluid in the back circuit today because it looked dirty.
So I pulled off the other wheel & opened the bleeder. My assistant in place behind the wheel pushed the pedal down, up, down, up and so on. After I saw clean fluid coming out I went ahead and closed the bleeder. Except that it was leaking. I gave it a little more of a turn.

Stripped out the wheel cylinder bleeder valve hole.

Wonderful. It's a holiday, no way am I getting another wheel cylinder today. Can't drive it to work tomorrow & our van has engine problems. Sometimes you really wish you had left well enough alone.

My other cylinder isn't stripped but it was leaking. Too bad I don't have a rebuild kit.
 
Well I took both cylinders apart, picked out the best looking seals and cleaned it all up as good as possible then put one "good" cylinder together.

Bled both sides again & tried her out.

This will work for a while, I don't know how long but I have officially reached my quota of brake work for a while. /bcforum/images/%%GRAEMLIN_URL%%/wall.gif
 
Rick, as others have said, and (for once) I listened to good advice in redoing my rear axle... Don't bother trying to rebuild the cylinders. I think mine were $18 a set, or maybe that was per side. Either way, not worth trying to pull them apart, rebuild them, new gaiters, etc... toss 'em, slap in new ones, and be done with it.

I ordered my parts from Harold Rininger (see https://stores.ebay.com/Harolds-TriumphMG-Parts) who was inexpensive and quick to ship, and had bearings & wheel cylinders in stock. I'm sure that Tony, and others here, would be able to supply also.

My $0.03 (Canadian)
 
Thanks Duncan, the local NAPA auto parts has access to 140+ in a warehouse about 20 miles from here.
If I call them tomorrow morning they will have one for me by noon. They cost $20 US each.

I was simply not thinking I should replace both at the same time, so I only ordered one. Oh well, tomorrow morning I'll ask them to get me another & it will be ready for me when I get home from work.

"Rebuilding" the one I have simply allows me to go to work tomorrow.

It's the classic question - what do you do if you lose all the lug nuts while changing a tire? Or- what happens if you strip out the bleeder on the second side trying to bleed the brakes after you replaced the first side and you don't have a spare cylinder? Make a good one out of two bad ones.
 
AAAh, gotcha! Well, you know the old joke... brakes, manual trans, and a horn; any two out of the three, and you're good to go! Just don't tailgate anyone with a heavy brake foot. /bcforum/images/%%GRAEMLIN_URL%%/wink.gif
 
uh - oh...
My horn isn't working! /bcforum/images/%%GRAEMLIN_URL%%/cryin.gif
 
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