TR2/3/3A What's wrong with this brake fluid? TR3

[Got_All_4]

This fluid came out of my TR3A after a brake and clutch master cylinder rebuild. Not a pretty sight. I know I accidently mixed dot 4 & 5 together a couple of years ago. However there is much more then just the 2 fluids.

I was flushing with new dot 4 and I'm sure that's what the bottom layer is and the top is dot 5. The second pic is looking from the top with a light underneath. Can't figure out what that layer of bubbles are. Could that be water ? As I was bleeding some of the bubbles acted like water on oil. I would think that it would go to the bottom.

 

[Got_All_4]

Top view

 

[Got_All_4]

Went to the back brakes and was going to bleed and inspect them when I found this mess. Looked like fluid had been leaking for a while and crystallized around the boot which has been separated from the cylinder. Another dilemma is looking in the parts books I may have the wrong cylinders in the car. Can anyone tell me what would correct? My commission # starts as TS667. There are flat top pistons in the cylinders and i believe that they are to be slotted. I have a box of old parts cylinders ( I'm probably the only one who keeps junk) probably from the original rebuild and they are all slotted.

 

[TR3driver]

Not likely to be water, if that is really DOT 4. DOT 4 will suck up water. But I don't know what else it would be, unless someone has added something besides brake fluid.

Flat pistons sound right, for the late brakes. The slots were for earlier brakes that didn't have the hold down nails.

 

[vivdownunder]

With the brake fluid, try pouring a bit of water into some DOT4 fluid and see if it replicates what came out.

I've seen both slotted and plain wheel cylinder pistons among the 3 x types used on Girling rear brakes.

The slotted piston was important in locating the shoe when it just sat against a midway peg. But less important when keepers were introduced to hold the shoes against the backing plate, as with your car.

Viv.

 

[Got_All_4]

Just noticed that the driver side cylinder is loose. With little pressure it slides. Is this ok?

 

[Got_All_4]

Also the driver side has no indication that it was leaking brake fluid. However the brake shoes were wet just like the other side. Could the axle seals be leaking and throwing oil and oil soaking the shoes?

 

[TR3driver]

Could the axle seals be leaking and throwing oil and oil soaking the shoes?

Definitely a possibility, had that problem on my TR3 last fall. Fortunately I noticed the drip before the shoes got contaminated.

But note that it's the inner seal that holds back oil; the outer seal (the one that is hard to get at) only holds grease.

 

[TR3driver]

Just noticed that the driver side cylinder is loose. With little pressure it slides. Is this ok?

Yes, they are supposed to be able to slide around a little, so the force is applied more-or-less evenly to both shoes.

 

[Got_All_4]

TR3driver how hard was it to replace those seals?

Also should I replace the rear passenger cylinder?

 

[Geo Hahn]

TR3driver how hard was it to replace those seals?...

I'm not Randall but I had a similar leak on my TR4. Unfortunately the first I realized it was happening was when the friction material separated from the metal shoe, 500 miles from home.

I was convinced by a 'TR expert' (no one here) that I should replace both the hub seal and the axle seal. He then demostrated how easily a 3-legged puller can destroy a hub. One used replacement hub later I did replace both seals, though I think it very likely I only needed to replace the axle seal which is the (much) earier of the two.

The manual outlines the procedure well -- the only tricky bit is setting the float correctly. In addition to a dial indicator you may need to have a small assortment of shims to adjust the float.

 

[TR3TR6]

The oil seal on my TR3A started leaking and I ended up with a small puddle on the floor. I thought it was break fluid at first, but when I removed the wheel and hub, everything was soaked in oil. Your picture looks like it had water or something that caused it to corrode the metal. Oil wouldn't have caused the metal to rust.

 

[TR3driver]

TR3driver how hard was it to replace those seals?

Not too bad, although somewhat tedious. Turn the locktabs and remove the 6 bolts that go into the bearing housing from behind the backing plate. Then you can slide the entire axle assembly out with the hub still attached. I immediately stuck a bolt & nut through one of the holes to keep the backing plate in position (so it didn't slide off and hang on the brake pipe). Pry the old seal out, tap a new seal in. Smear the sealing surface on the axle with some grease, and slide it back into place. Install the 6 bolts with new locktabs, but don't turn the tabs just yet. If the end float was good before, it should still be OK (but mine was way out of whack). If yours is off, you'll need to add or subtract shims.
<div class="ubbcode-block"><div class="ubbcode-header">Quote:]
Also should I replace the rear passenger cylinder? [/QUOTE]
Frankly, that damage looks like brake fluid to me, plus switching fluid types can sometimes cause problems with old seals; so at the very least I would change the seal in the cylinder (maybe even both of them). But there is a good chance that the bore is damaged as well, which means a new cylinder.

Funny thing is, you said it had DOT 5 in it; and DOT 5 won't do damage like that. Could it have been leaking before you put in the DOT 5, and not been cleaned up? Or is it possible you got "synthetic" or DOT 5.1 (neither of which is the same thing as DOT 5)?

 

[Got_All_4]

I I probably put in new Gerling cylinders back in the late 70's when I first rebuilt the car. I know over time I've add fluid. About 4 years ago I had to rebuild the front calipers. The pistons were frozen up so I used stainless pistons this time so I shouldn't have to worry about that again. That's when I think dot 5 was accidently introduced to the system and I'm sure it was just dot 5. That is what I used in the TR250 from day 1.

For sure I'll replace the passenger side. Looks like it could even be rebuilt be on the car if the cylinder is ok. If I replace both sides I'll be tempted to flush the system and use dot 5. However what Do I use to flush the lines? Another concern is the front calipers. Do I flush them too or just the lines? Or should the calipers be dismantled and cleaned. The manual says to use mythelated spirits. Know one here has ever heard of that. An old Triumph technician from our local dealership said to use isopropyl alcohol but didn't say whether to flush through the calipers.

 

[CJD]

I would vote for dismantling to clean. The reason is all cylinders and calipers bleed from the top...so you cannot get the fluid out by bleeding...


For the same reason, I would not flush alcohol into the calipers...it won't come out unless you take it all apart. Only flush the lines.
John

 

[TR3driver]

Methylated spirits is another name for denatured alcohol. But the list of possible denaturing agents includes some things that might not be safe for brake seals, so I wouldn't want to let it touch the seals. Supposedly methanol (methyl alcohol) is safe for the seals, and that is what I used many years ago. Had to ask at the drug store for it, though, they keep it behind the counter.

But the last few times I've converted to DOT 5, I've just bled at each wheel until I get clean purple fluid and let it go at that. Seems to work fine.

 

[Got_All_4]

I'm a little concerned about the moisture in the lines. dot 4 as we know absorbs it. Alcohol will get rid of it during flushing. These cars sit here for 5 to 6 months in a cold environment without pieces parts moving. I try to run them every chance I get in the winters to keep things loose. Steel pistons in an aluminum body whit moisture in the lines add and just sitting around is a recipe for disaster.

 

[sp53]

I think I would flush it out with dot 5 also. It might get kinda spendy, but it should work the best. I suppose you could even unbolt the calipers and hang them upside down and do some gravity bleeding with the bleeder out if you are worried about trapped fluid.

 

[Got_All_4]

All good info. I like the hang upside down to drain brake fluid and removing the entire hub assembly in one piece. Can I get to the bearings do it that way?

 

[TR3driver]

The bearings remain trapped by the hub. If you want to change them, you'll also want to find the proper tool to separate the hubs from the half shafts (or else send the shafts off to be separated). As Geo noted, trying to use an ordinary hub puller is a good recipe for ruined hubs.