[Bob Lincoln]

Found the other day that the LR wheel cylinder on my 93 Daytona is leaking fluid. Luckily I caught it in time, before anything bad happened. The cylinder is coated with wet dust, and about an inch of lining is contaminated.

I'll be replacing the linings, hold-down hardware, drum (because it's Chinese). I'm going to buy new wheel cylinders (doing both sides), hoping to unscrew the brake line from the cylinder without damage, but that's uncertain. I'll also buy a rebuild kit in case I can't get the cylinder off without bunging up the rigid line. I see that, unlike some cars, it looks like I can get the guts of the cylinder out without unbolting it, there's clearance for the pistons and seals. New would be better.

In case I can't remove it, has anyone ever rebuilt a wheel cylinder, and done it without honing the inside, and reinstalled it with no leaks? This has 207K miles on it, not sure what the inside of the cylinder will be like.

I was going to do a full fluid change anyway, this summer. Now I'll be doing all the rear hardware, plus I have some front pads and rotors waiting to go on. Will do those and rebuilt calipers.

Lesson: Pull and inspect every year.

 

[DakotaDan]

Just did both of my rear wheel cylinders this weekend. Mine were not leaking past the outer seals, but I pulled the seals back and saw fluid. I also found that the original wheel bearings had plastic cages on them, so those went in the bin as well.
I have, in the past, tried to just put new guts in a wheels cylinder without honing. Bad move it will leak again very, very soon. If you remove the two small bolts holding the wheel cylinder to the backing plate, you can pull the cylinder away enough to be able to get a flexible shaft hone in there without pulling the line off. Lot's of penetrating oil and back and forth wrench motion got mine broke free. New parts were wheel cylinders, brake shoes, drums, all four bearings and spindle grease seals, My theory is while I got it apart, do it all and not have to do it again. All this work was due to our mandatory annual PA vehicle inspection. Some people are not fans of it, I appreciate the fact that they check all this stuff every year.
Dan P.

 

[Bob Lincoln]

The SKF inner bearings have the yellow plastic cages. They look scary, but I've run them 50K miles with no issues, and they're said to be lower friction. It's all I can find online for my car.

I think the way to go is to cut the line and unscrew it from the back flex hose with a socket wrench, and toss the cylinder, and use new rigid line. There are standard lengths that will reach.

 

[Bob Lincoln]

So, did you, or has anyone, honed the wheel cylinder while it's bolted in place to the backing plate, and connected to the fluid line? That's what I'm facing. It's either that or cut out ALL the brake line in the car. Unfortunately, the rigid line from that wheel goes to a short flex hose at the trailing arm of the axle. I absolutely cannot get tools or even fingers in there to undo the rigid line, because the exhaust pipe is so close to the trailing arm. I'd rather replace it all, but circumstances don't allow it now. If I can safely hone the cylinder while bolted to the backing plate, I can re-assemble with the rebuild kit that I have, and make it safe.

Then I can get my garage with lift built, and work in it up in the air this winter, replacing it all.

 

[Bob ONeill]

Years ago I did that. The 'left over' brake fluid help to 'lube' the honing process. I think I still have the honing tool, somewhere. It's self centering and works great. You only hone to remove any residue and corrosion or, hone as necessary until the cylinder is clean. Then wipe it out, 'tap' the brake to remove any honed material from the brake line, clean it agin and using fresh fluid, reassemble the unit with new parts.

 

[Bob Lincoln]

Thanks. It's $17 at Advance Auto, going to pick one up now. The entire system will get new fluid. And regardless of the condition of the RR cylinder, I'll hone and rebuild that now, also.

 

[Bob Lincoln]

So I tried unscrewing the line today, after spraying it twice a day for a week. The nut turned, but the line was also twisting slightly at the nut. I could see that it would be compromised. So I unbolted the wheel cylinder and unscrewed it. Then I got a hacksaw blade and cut off the other end of the rigid line and used a socket to remove it from the back of the flex hose. The access is awful back there, by the trailing arm. Used a 30" pre-terminated line to make up the 27" factory line, with some slack in the bends. Connected all the plumbing and attached the new wheel cylinder, put the new shoes in, etc. Tried to install the new drum, and it won't fit over the brakes.

I've had that problem lately, and it occurred to me that the starwheel, which is turned in all the way, may not be assembled right. It comes apart into two pieces, and the one with male thread and the wheel fits into the side that has internal threads, but it's a slip fit, they don't screw together. I think I have to strip down the hardware and check the starwheel again.

Oh, and I have two rust holes through the backing plate - one above the lower spring and one near the rear nail for the hold-down spring.

And I had Kathi set the parking brake to make sure the cable is not frozen, and the return spring on the cable was rusted, broke into two pieces that overlap each other. It still works, but I need to replace it if I can find one. Rockauto shows one, but the picture may be inaccurate, as it displays the bottom shoe spring, but calls it the parking lever return spring.

Anyway, I was successful in fixing the fluid leak. I'm going to replace the RR parts, and the front calipers, rotors and pads. So bleeding won't be an issue. It will take another week, but it will be back on the road and much safer, should brake better.