On my 1997 Nissan Pathfinder with 193,000 miles, I changed the drums, shoes, and all hardware yesterday evening. Immediately after I noticed severe pulsations in the brake pedal, so I figured I must have received out of round drums. I swapped back in my old original drums which aren't warped but were just worn down over the 25 years of use, and the pulsations are completely gone. I'm sending these back and will get a new set of drums to replace again. Do I have to change shoes again or can I get away with using these new shoes on the drums when I receive it?
I'll end up putting less than 100 miles on the vehicle by the time the new drums arrive.
Should new drums need to be machined? Or was this just a case of a defect?
It was a defect, new drums are not supposed to be machined.
If you are unable to grind the brake shoe linings to conform to the drums they will wear in themselves after several stops.
Just put on the new shoes and new drums and allow a little while for the new shoes to wear in and conform to the new drums, like @chucktobias said.
When using new drums the shoes must be ground to match the circumference of the drum.
Should new drums need to be machined? Or was this just a case of a defect?
I don't understand why you think there is a defect in the drums. New drums are not machined. Brake shoes are machined to match the new drums.
Apparently the new drums were out of round.
If you are unable to grind the brake shoe linings to conform to the drums they will wear in themselves after several stops.
So you're saying the new shoes I put on can be kept when the new drums go on in a few days?
I guess to avoid problems ill just change them again, but is that what you meant?
Yes, the shoes will wear into the drums. Braking power will be reduced until this happens but will probably not be noticeable with front discs. (With 4-wheel drum brakes it's very noticeable.)
I don't understand why you think there is a defect in the drums. New drums are not machined. Brake shoes are machined to match the new drums.
Yeah the new drums were out of round. As soon as I had them on when brake job was done, the pedal was pulsating severely on highway and even local speeds. Put my old drum back on and it went away.
What I was essentially asking is I’m getting a set of new drums again this weekend. Do I have to change shoes again?
No need to change the shoes unless they get badly chewed up. As I said before just be prepared for a bit less braking action in the rear while the shoes wear into the new drums. (You'd have that anyway even with new brake shoes unless they were arced to match the new drums before installation.)
No need to change the shoes unless they get badly chewed up. As I said before just be prepared for a bit less braking action in the rear while the shoes wear into the new drums. (You'd have that anyway even with new brake shoes unless they were arced to match the new drums before installation.)
Okay, thanks
So it turned out to be the shoes that were causing the issue. The Powerstop shoes I received that was stated to be for my vehicle was noticeably bigger than Bendix brand and Autozone brand shoes. So I put on new shoes from Autozone and put the new drums back on and no more vibration or pulsation.
However, I'm noticing the passenger side is running a lot hotter than the driver side. I can't touch the passenger side or ill get burned but the driver side I am able to touch for a few seconds. My vehicle self adjusts with the handbrake. I turned the star adjuster enough to lightly drag the drum on both sides when I changed the shoes and reinstalled drum on Sunday and the passenger side got pretty tight. I took off the wheel today and slacked it back off a bit.
How hot should drums get after normal driving city and highway and what could be causing temp difference? Nothing is binding and I have new hardware, cylinder, and lubed all contact points.
How hot should drums get after normal driving city and highway and what could be causing temp difference? Nothing is binding and I have new hardware, cylinder, and lubed all contact points.
Interesting, so it was the brake shoes causing the pulsating.
The only thing that would be causing higher temperature on one side is more friction on that side. There's nowhere else it would be coming from. It would be interesting to see what actual temperatures are using an infrared thermometer.
Considering that brake shoe manufacture and/or relining is a precision process, it's surprising there would be problems...
that's a high tech facility right there. The finest quality control. Where are these units headed ... Landrover?
@mmj, Nah, Land Rovers would have 4-wheel discs probably with high-tech carbon fiber pads and premium rotors, probably Audis as well...
you can see at 3:55 how round those rotors come out
So I checked with an infrared thermometer after some highway and city driving. The driver side drum is coming in around 130 degrees at the face of the drum and the side where the pads would touch on the inside of the drum are around 140-143 degrees.
The passenger side is 134-139 degrees at face and around 148 at the side. So they’re not far off really.
I know, top notch production right. Since readjusting the passenger side yesterday evening, after highway and city driving this morning they were not hot. I can place my hand on each drum for over 10 seconds. I’ll be getting an infrared thermometer to check the temps, but hopefully it doesn’t over adjust itself.
So I checked with an infrared thermometer after some highway and city driving. The driver side drum is coming in around 130 degrees at the face of the drum and the side where the pads would touch on the inside of the drum are around 140-143 degrees.
The passenger side is 134-139 degrees at face and around 148 at the side. So they’re not far off really.
that's about what I would expect