How hot should new brakes and discs gets?
Discussion
I replaced the front discs and pads today and so far they seem to be running a lot hotter than they were before. They did smoke after the first time I stopped (an idiot cut me up so had to brake harder than I had anticipated) but I assume that was just all the oil and other crap that they coat them with at the factory burning off as it didn't happen again.
When I stopped and got out, I noticed that the tyres were a lot hotter than normal which I'm guessing is the heat from the brakes soaking into them. Is this normal during the bedding in process?
I've looked online and all I can find is people saying "Check the callipers" or "Check the slide pins" etc. The callipers aren't seized and the piston moves freely, the slide pins also move easily and slide in and out with ease. I've jacked the car up and rotated both front wheels and there is no resistance at all, no binding happening so the pads aren't constantly rubbing or anything.
The brake fluid is also below the maximum as I had to take some fluid out after pushing the pistons back. I'm also using good quality pads and discs, not some cheap Chinese brand that no ones ever heard of!
When I stopped and got out, I noticed that the tyres were a lot hotter than normal which I'm guessing is the heat from the brakes soaking into them. Is this normal during the bedding in process?
I've looked online and all I can find is people saying "Check the callipers" or "Check the slide pins" etc. The callipers aren't seized and the piston moves freely, the slide pins also move easily and slide in and out with ease. I've jacked the car up and rotated both front wheels and there is no resistance at all, no binding happening so the pads aren't constantly rubbing or anything.
The brake fluid is also below the maximum as I had to take some fluid out after pushing the pistons back. I'm also using good quality pads and discs, not some cheap Chinese brand that no ones ever heard of!
Perhaps it is just normal operation and you are a bit obsessed having just changed them. How much attention did you pay to the wheel temps before the change.
Also on a lot of new pads, they are sintered (edges are sliced off) to allow bedding in. This will mean that there is less pad contact area doing the same job which obviously equals more heat.
I'd wait a few hundred, up to five hundred miles for them to bed in.
Also on a lot of new pads, they are sintered (edges are sliced off) to allow bedding in. This will mean that there is less pad contact area doing the same job which obviously equals more heat.
I'd wait a few hundred, up to five hundred miles for them to bed in.
"A few hundred miles for them to bed in"??
Bed them in properly. Stops from progressively faster dwn to walking speed, up to the fastest you will use, trying to avoid a fade. Don't stop, keep moving, then drive normally to let them cool down. Done. Thirty minutes, 20 miles? Obviously, yiou need to choose time and place to do this.
John
Bed them in properly. Stops from progressively faster dwn to walking speed, up to the fastest you will use, trying to avoid a fade. Don't stop, keep moving, then drive normally to let them cool down. Done. Thirty minutes, 20 miles? Obviously, yiou need to choose time and place to do this.
John
t400ble said:
Did you not degrease the discs prior to fitting?
^^^ this.You will be working the brakes hard just to burn the protectice grease off. Quite possible you have contaminated the pad surface now. Will be working harder than should be for the same stopping power.
What brand pads/discs? What car?
No way should new brakes get hotter than the older ones. Exact size replacements?
t400ble said:
Did you not degrease the discs prior to fitting?
Yes, they were thoroughly cleaned with brake cleaner. This is apparently normal as it's caused by something called polymerization. MikeStroud said:
Are you sure the pistons are not sticking in the calipers? I had this after a change and the pads were constantly applying pressure to the discs and getting hotter than normal.
Yep, pistons are not sticking, slide pins are free and the wheels don't drag or bind when rotated off the floor
I managed to wash the car which caused the discs to oxidise very quickly indeed. Both sides kept their "rusty" look until the brake pedal was pressed whilst moving so I would guess that it means they're definitely not binding?
One thing I did notice was the passenger side disc is completely clear of all the rust, both front and back. As for the drivers side disc, it's clear of rust on the back but has various patches of rust still on the front.
Not sure if the picture will be of any help to anyone? Both pads are seated in the same way on both calipers. Could one pad maybe be defective or something?
One thing I did notice was the passenger side disc is completely clear of all the rust, both front and back. As for the drivers side disc, it's clear of rust on the back but has various patches of rust still on the front.
Not sure if the picture will be of any help to anyone? Both pads are seated in the same way on both calipers. Could one pad maybe be defective or something?
MarkA67 said:
I managed to wash the car which caused the discs to oxidise very quickly indeed. Both sides kept their "rusty" look until the brake pedal was pressed whilst moving so I would guess that it means they're definitely not binding?
One thing I did notice was the passenger side disc is completely clear of all the rust, both front and back. As for the drivers side disc, it's clear of rust on the back but has various patches of rust still on the front.
Not sure if the picture will be of any help to anyone? Both pads are seated in the same way on both calipers. Could one pad maybe be defective or something?
Discs look good, but perhaps that pad somehow hasn't got a completely flat surface, a few big stops should get it better.One thing I did notice was the passenger side disc is completely clear of all the rust, both front and back. As for the drivers side disc, it's clear of rust on the back but has various patches of rust still on the front.
Not sure if the picture will be of any help to anyone? Both pads are seated in the same way on both calipers. Could one pad maybe be defective or something?
MarkA67 said:
I replaced the front discs and pads today and so far they seem to be running a lot hotter than they were before. They did smoke after the first time I stopped (an idiot cut me up so had to brake harder than I had anticipated) but I assume that was just all the oil and other crap that they coat them with at the factory burning off as it didn't happen again.
When I stopped and got out, I noticed that the tyres were a lot hotter than normal which I'm guessing is the heat from the brakes soaking into them. Is this normal during the bedding in process?
I've looked online and all I can find is people saying "Check the calipers" or "Check the slide pins" etc. The calipers aren't seized and the piston moves freely, the slide pins also move easily and slide in and out with ease. I've jacked the car up and rotated both front wheels and there is no resistance at all, no binding happening so the pads aren't constantly rubbing or anything.
The brake fluid is also below the maximum as I had to take some fluid out after pushing the pistons back. I'm also using good quality pads and discs, not some cheap Chinese brand that no ones ever heard of!
What an utterly moronic thread.When I stopped and got out, I noticed that the tyres were a lot hotter than normal which I'm guessing is the heat from the brakes soaking into them. Is this normal during the bedding in process?
I've looked online and all I can find is people saying "Check the calipers" or "Check the slide pins" etc. The calipers aren't seized and the piston moves freely, the slide pins also move easily and slide in and out with ease. I've jacked the car up and rotated both front wheels and there is no resistance at all, no binding happening so the pads aren't constantly rubbing or anything.
The brake fluid is also below the maximum as I had to take some fluid out after pushing the pistons back. I'm also using good quality pads and discs, not some cheap Chinese brand that no ones ever heard of!
Exactly how are you deciding that the discs and tyres are 'hotter than normal'?
You need to take your car to a decent garage in the future to let them do the job and get on with what you're supposed to be doing.
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