Treb
Treb Reader
2/9/12 9:47 p.m.

Drove my MGB today. (front discs, rear drums; recently rebuilt calipers, new discs, pads, and new m/c)

Once or twice, the right front caliper was "grabby" at low speeds. Slowing down with light pressure on the pedal, it was fine until ~5mph, then it would lock up. Would release again once the car stopped, and be fine.

Could it be that the discs are just dirty -- get 'em good and hot and burn off the crap? I dunno; it's the best I can come up with. Discs look fine on a quick visual inspection.

Ideas? Thanks Matt

TRoglodyte
TRoglodyte HalfDork
2/9/12 10:15 p.m.

Burn em off and "feel " for front or back .

iceracer
iceracer SuperDork
2/10/12 7:43 a.m.

Sticky caliper slides or sticky piston are other possibilities. But as said, often some hard braking will free things up.

corytate
corytate HalfDork
2/10/12 8:06 a.m.

whenever I turn rotors and sand the pads or put new pads and rotors on, I burn the hell out of em before the customer gets them. I find a relatively abandoned stretch, ride the brakes going about 30, and do some hard stops. not abs stops but close to that. its turned out good for me so far.
Had one the other day that the caliper tried sticking on the first hard stop when I let up but that went away after a couple more stops

wlkelley3
wlkelley3 Dork
2/10/12 11:16 a.m.

Had that problem on my Opel GT. Got worse over little time and the front would lock up right before the car stopped, causing it to skid to a stop. Then would take moving the car in gear to unlock. Took me a while to figure it out. What was happening on mine is the rubber hoses in front would swell shut or almost shut. Fixed by replacing the front rubber hoses, I went with upgraded lines that are steel braided under a outer rubber coating.

spitfirebill
spitfirebill SuperDork
2/10/12 11:24 a.m.

Could be the rubber brake lines.

Treb
Treb Reader
2/10/12 8:59 p.m.

Okay, on further review, it's the right rear drum that sticks.

Only one flex line to the rear axle (and it's braided), so I think a failure there would do both rears.

One drum grabs, I'm thinking a leaky wheel cylinder and/or broken springs/fittings? I'll open it up tomorrow.

Matt

wlkelley3
wlkelley3 Dork
2/10/12 10:34 p.m.

Rear drum...Yes you going the right way. Wouldn't necessarily stop at just the right side. I'd check the other side too. And as I've learned the hard way, whatever you do to one side do to the other. If something broke or leaks on one side the other side will soon follow. Most likely as soon as the weak link is fixed. That's what happened to me. Had a leaky rear wheel cylinder and replaced it. While bleeding the system the other side failed and I had to order another wheel cylinder and wait for it to come in. With Opels you just don't go to the local parts store. And it's the same for MG's. Have one of those too.

Treb
Treb Reader
2/10/12 11:20 p.m.

Will definitely do both sides... last time I did these drums, the springs were a local parts store thing, but the wheel cylinders are definitely not.

Trans_Maro
Trans_Maro Dork
2/11/12 12:02 a.m.

Did you put the shoes on in the correct positions?

Shawn

Treb
Treb Reader
2/11/12 10:07 a.m.

Yes... last time I did the drums was ~8 years ago; worked fine until this week. I think I may have put them in backwards once, many years ago.

Matt

Trans_Maro
Trans_Maro Dork
2/11/12 10:23 a.m.

Ahh, my mistake, I thought you'd just done the drums.

Maybe a return spring has let go.

Shawn

AngryCorvair
AngryCorvair SuperDork
2/11/12 12:42 p.m.

or a weepy axle seal...

Treb
Treb Reader
2/12/12 10:36 p.m.

Weepy axle seal it is.

As it happens, I meant to do them last time I had the drums apart -- the aforementioned 8 years ago -- so had the seal on the shelf. I didn't have the slave cylinders or the springs; so it's just as well.

Will inspect again in a few hundred miles and see how it's doing.

Thanks for the suggestions. Matt

AngryCorvair
AngryCorvair SuperDork
2/13/12 10:23 a.m.

... (pats self on back) ...

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