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Author Topic: Diagnosing issue with rear caliper  (Read 2961 times)

Offline dennis10

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Diagnosing issue with rear caliper
« on: November 26, 2024, 03:25:31 pm »
Hi chaps, 

I'm not swimming in cash so would really appreciate some advice on correctly diagnosing my rear nearside caliper issues so I don't fire the parts cannon at it.

This is the offside, which I think is good and the pad sweep on the disc is nice and clean:



This is the nearside which I think is the offending side, the pad sweep on the disk is not clean and looks like something is stuck:



Taking the handbrake off this morning, it was clear it was still stuck on the disk as when I tried to pull away there was a thunk as the pad released a bit from the disk as I reversed out.
If you look at my photos you can also clearly see that the sweep of the pad on the disc is not clean and it is not seating properly, suggesting something is stuck, I'm just not sure if it is dodgy handbrake cables, dodgy handbrake mechanism on the caliper or the caliper piston itself being seized up.  Is there an easy way to diagnose which it is?  I know I probably need discs and pads soon anyway on the rear which is not a problem, but if I can avoid buying a caliper because it is something else causing the issue then I'd like that option

Cheers



Offline ZoliWorks

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Re: Diagnosing issue with rear caliper
« Reply #1 on: November 26, 2024, 04:33:54 pm »
Rear calipers are a common failpoint in the Mk5. They like to seize up, especially if left sitting for longer periods of time or being exposed to the elements.
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Offline Octoparrot

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Re: Diagnosing issue with rear caliper
« Reply #2 on: November 26, 2024, 05:20:30 pm »
Rear calipers are a common failpoint in the Mk5. They like to seize up, especially if left sitting for longer periods of time or being exposed to the elements.


Yes I agree, probably a seized / seizing caliper, common problem, I wouldn't bother trying to refurb it yourself, get a refurbed caliper from a reputable supplier.

Offline Flyingscotsman

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Re: Diagnosing issue with rear caliper
« Reply #3 on: November 26, 2024, 05:51:55 pm »
The OEM ones are made by TRW.  You can get red powdercoated TRW ones for similar price to refurbs.
I replaced both my rear calipers with these last year.

https://brakeparts.co.uk/shop/Volkswagen/Golf/05-08/GOLF%20MK5%202.0%20inc%20GTI/Rear%20-%20Brake%20Calipers%20and%20Wheel%20Cylinders/BCA3894D

Offline dennis10

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Re: Diagnosing issue with rear caliper
« Reply #4 on: November 27, 2024, 09:43:22 am »
Thanks for the reply guys.

That
The OEM ones are made by TRW.  You can get red powdercoated TRW ones for similar price to refurbs.
I replaced both my rear calipers with these last year.

https://brakeparts.co.uk/shop/Volkswagen/Golf/05-08/GOLF%20MK5%202.0%20inc%20GTI/Rear%20-%20Brake%20Calipers%20and%20Wheel%20Cylinders/BCA3894D


Does anyone know why there are some calipers with a 41mm piston and some with the smaller 38mm piston?  This one that you linked to is for the smaller 38mm piston, is this what would be on my Edition 30?

Offline Lewo

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Re: Diagnosing issue with rear caliper
« Reply #5 on: November 28, 2024, 07:51:26 am »
R32s have the 41mm pistons for 310 mm discs. Your Ed would be 38mm too..
Caddys might be 41mm too.

Offline dennis10

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Re: Diagnosing issue with rear caliper
« Reply #6 on: November 28, 2024, 10:11:54 am »
R32s have the 41mm pistons for 310 mm discs. Your Ed would be 38mm too..
Caddys might be 41mm too.

Cheers!  -  I'm now thinking of upgrading the rears to mk5 R32 / Mk6 R 310mm vented brakes, since I'm loathe to spend money on a simple replacement if I can upgrade for not much more.  I think all I need are calipers/carriers and 310mm vented discs.  Since I'm looking at a replacement NSR caliper anyway as well as discs and pads at the rear soon, I might as well upgrade.

If anyone has some favourite places to buy these cheap, please share!  Calipers and discs dont seem too bad, but the cheapest I've found the carriers for so far is £70 each which is crazy money