Changing The Rear Rotor In The Dark For Fun

[NorCalDoug]

Well...no...not really for fun.

The wife's was making an odd rubbing noise, which seemed to be coming from the DS rear tire. The told me that the brakes were behaving in a weird way, so I took it for a quick spin -- yeah...that's not right.

Felt very grabby and a little clanky. Not normal at all.

It had been raining for much of the day, but had cleared up -- it's about 7PM and quite dark. My garage is a mess, so there's no pulling it in there to work on it. I backed the rig up the driveway and next to the house -- I would work by porch light. Note to self, get a set of those portable work lights next time they're on sale

I pull the rear DS tire and look at the caliper...it looks okay from this side. The rotor feels fairly smooth. I removed the 2 sliding pins and pulled the top part of the caliper off. Checking the back side of the caliper revealed an unpleasant surprise...there's NO BRAKE PAD! Greeeeeaaaat....

Running my fingers carefully along the backside of the rotor I could feel deep grooves -- well...that explains the odd rubbing noise. Where did the pad go? Regardless of that...the rotor needs to be replaced. Fortunately for me, I have a set of rear rotors that I purchased from a local forum member who had to sell his 80 a few months back. He sold off his extra parts, I picked them up at a very good price. I have a pair of ceramic brake pads from him as well...so I'm set with replacement parts.

Good thing the rear rotor is SO easy to replace. I removed the rest of the brake caliper housing deal -- the rotor slid out with just a little coaxing.

Hey! There's the other brake pad. WTF? How did it slide back there? Somehow the pad slid out and lodged itself behind the rotor -- it was sitting at aprox. 11 o'clock. I pulled it out. Wiped the dust off everything and got the new rotor cleaned up with a bunch of brake cleaner and blue shop towels.

The caliper piston looks a little worn now from having come in contact with the rotor, but seems to work fine. There doesn't appear to be any damage to the caliper itself.

I reinstalled everything in about 20 minutes. A quick road test followed -- no more grinding, but there is a faint squeeal coming from the same rear wheel. The squeel goes away when I brake.

I have Friday off (my future brother-in-law is going to have his bachelor party -- I'm heading to Tahoe for that ) so I'll replace the PS rear rotor and pads then. I like everything to be even.

Thoughts on the DS caliper piston? It has a few small grooves in it, but it's not torn up. Should I replace it? Again...it looks okay to me...but I'm nothin' but a 1 shade tree 80s owner...what do I know...

Sorry...no pics of the carnage, but I did save all the parts, so I can post up pics if there's a demand for it.

 

[Tools R Us]

The main question is why did it spit the pad? Was it bald, close to metal to metal? Was the old rotor thin, under spec? Caliper bolts loose? If the piston is only slightly scored it's OK to run it, but determine why it spit the pad, you don't want that happening again on moma's truck!

 

[Tools R Us]

Most of the time a brakes off squeal is from dry pad to caliper contact points, put a skin of brake grease anywhere the metal backing plate of the pad contacts the caliper frame to shut it up.

 

[Romer]

Glad you got it figured out Doug. Too bad you didn't take pictures, you could have added to the FAQ.

I am sure Momma was happy you were working on her rig. Did you get the armor installed yet?

 

[IdahoDoug]

IIRC, the rears are a single piston design. Sounds like the caliper cage got sticky, which meant that the piston side was wearing and moving but the outboard pad was not. Eventually the inner pad got quite thin. Then the caliper cage started moving again and the outboard pad wore to the point it allowed the worn inner pad to slip out of the caliper side of the caliper. Interesting.

So the inner pad was worn quite a bit thinner, eh? Were these factory pads and is/was the factory shim and anti squeal shim there?

DougM

 

[DaveyBoy]

I pull the rear DS tire and look at the caliper...it looks okay from this side. The rotor feels fairly smooth. I removed the 2 sliding pins and pulled the top part of the caliper off. Checking the back side of the caliper revealed an unpleasant surprise...there's NO BRAKE PAD! Greeeeeaaaat....
.

I think I got you beat!! - you CA boys really have it tough out there )
My PS rear did the same thing except it destroyed the caliper piston
and the rotor, while floating around in there.
Took it apart at night, with porch light, in 20 degree windy weather!
Oh, and 5 miles, uphill, both ways, in the snow!!

 

[Brentbba]

E-brake set to tight Doug?

 

[IdahoDoug]

E brake is a separate inner drum brake, so not sure how it would impact the disc caliper.

DougM

 

[Brentbba]

E brake is a separate inner drum brake, so not sure how it would impact the disc caliper.

DougM

I know - was thinking about the squeaking noise, but it was all probably due to what he found. Learned alot myself changing the rear rotors.

 

[SUMOTOY]

We must assume it's not the ebrake since that should hang up all the time. My thinking is that you want to order up the 14USD rear boot kit for the caliper slider pins. They get gummed up pretty bad and impose on the release of the caliper. If they got hot enough, they start to melt and really impede retraction of the caliper. I've done 2 of these (93- customer, and 94 mine). I put light lube on the outside of the long boot to drive it in (I used a 6mm allen key wrench). Then clean up the pins with some scotchbrite and put a small amount of lube on the pins and put them in the new boots.

The kit gives you more than you will probably use, and is worth every penny on a rear pad change.

Scott Justusson

 

[NorCalDoug]

The inner pad was a little thinner than the outside pad -- it's difficult tell since it was lodged behind the rotor and lots of the pad material had been wornoff.

The sliding pin was devoid of grease, so I think IdahoDoug's point of the inner pad wearing faster might be what happened -- without grease, the caliper cage could've been stuck.

The outside pad was a little more than 2mm so it was close to replacement time.

None of the bolts were loose.
All were factory pads -- that's all I've ever used until last night.
All shims, anti-squeel, etc. have been used and were present.

 

[Brentbba]

Just glad that it appears that there was no real 'serious' damage done to either the cruiser or your wife Doug!

 

[NorCalDoug]

We must assume it's not the ebrake since that should hang up all the time. My thinking is that you want to order up the 14USD rear boot kit for the caliper slider pins. They get gummed up pretty bad and impose on the release of the caliper. If they got hot enough, they start to melt and really impede retraction of the caliper. I've done 2 of these (93- customer, and 94 mine). I put light lube on the outside of the long boot to drive it in (I used a 6mm allen key wrench). Then clean up the pins with some scotchbrite and put a small amount of lube on the pins and put them in the new boots.

The kit gives you more than you will probably use, and is worth every penny on a rear pad change.

Scott Justusson

I didn't know there was a kit for slider pins. I'll get one the next time I place an order.
I'll be keeping a close eye on the new pads and rotors for a while -- if I see any odd wear, I'll rebuild the thing.

Thanks for the tips guys!

 

[NorCalDoug]

Glad you got it figured out Doug. Too bad you didn't take pictures, you could have added to the FAQ.

I am sure Momma was happy you were working on her rig. Did you get the armor installed yet?

I'll snap a few pics on Friday when I do the other side and when I go back to check the side I did last night.

No armor installed yet -- it's still resting in the garage.

 

[Cruiserdrew]

Doug-I have a complete rebuild kit from Toyota that I have not gotten around to installing. If you are going to work on it, I can try and dig it up for you and you can replace when you get a chance. I even have the sliding pins, I think.

 

[NorCalDoug]

Andy,
That would be great! Thanks. I'll give you a call tonight.

 

[IdahoDoug]

Neat to see this board in action like that - a forum member may have exactly what he needs. AND he's in the same town. What are the odds?

Don't forget to properly torque the little allen head bolts that hold on the thin sheetmetal inspection plate on the calipers. If they get loose, you'll have a tinkling sound that will make you insane trying to pin down. Don't ask.....

DougM

 

[Darwood]

Neat to see this board in action like that - a forum member may have exactly what he needs. AND he's in the same town. What are the odds?

Considering it's Andy the odds are pretty good that he has the parts Doug needs.