Split piston Caliper Dust Cover

[semi-acoustic]

Hi All

I replaced my front pads and discs the weekend on my Nissan Serena, whilst doing so I noticed a split dust cover on one of the twin pistons.

In time I know this will cause issues and may cause the piston to seize up so I have two options. obviously with cost in mind.

1. To get a service kit and get a mechanic to do the job for me, (don't feel confident doing this myself), which will involve bleeding the brakes also.

2. Buy a used whole caliper from a scrappy which I have seen, pistons look a bit rusty but dust covers look fine, I can fit this myself and bleed the brakes I am told you cannot use emery cloth to clean as there is a seal on them.

If I go with option 2, what would you recommend to clean the pistons?

Any advice would be truly appreciated.

Semi-Acoustic

 

[Burnerman]

For sure, the job will need to be done.....our salty winters play havoc with calipers if the dust seal is no more.
On the replacement caliper, if the dust seals are intact then the pistons are likely to be good......they will be rusty on all exterior faces though. So check that you can open the bleed nipple! There is always a risk with second hand parts of course, either leaking seals or sticking pistons, either being an MOT fail.
Pistons can be cleaned up with wet and dry paper, preferably with some oil as a lubricant. (On the bench, obviously!)
Have you priced a replacement exchange caliper? Sometimes they aren't as expensive as you may think. Changing them over is simple, if they have the banjo bolt fluid fixing.
John

 

[empip]

'ScotchBrite' is very useful for cleaning (every toolkit should have a pack) - medium to fine - Cleaning pistons the pad side of the seal is not too dodgy.
Wash pads before use kitchen type pads may leave gritty residue in use - protect from unwanted ingress and clean thoroughly following use.
Some, not all brake fluid is hygroscopic - ie attracts and holds water - Thyis being one reason why car manufacturers spec' brake fluid changes every couple of years or so during the service cycle.
I am betting there is plenty of brake fluid sloshing around brake systems following years of use - unchanged.

http://solutions.3m.com/wps/portal/...ite-Hand-Pad-7448?N=7581709+3293241243&rt=rud

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[semi-acoustic]

Hi
Thanks for the very useful information, opted for the caliper from the scrappy, after using compressed air through the piece of cut brake pipe left on, the pistons responded and moved out all be it slowly, not together though , the dust covers are all ok so I gave it a good clean as suggested and removed the banjo bolt from the back and sprayed some WD40 in there.
I used a caliper piston tool to push back the pistons and used compressed air again quite a few times until they moved easier.

Any suggestions on what I can leave in there via the banjo bolt entry point overnight obviously not wanting to conflict with the new brake fluid and when you apply the brakes under normal braking conditions, do dual pistons move out at the same time?

Regards

 

[Burnerman]

Just use brake fluid alone inside the caliper, but feel free to use WD on the outside of the pistons if you want -at least it washes the grot away.
Don't worry about the pistons not moving together, they never do. So long as they move readily enough they should be fine.
John

 

[DaveHerns]

How about some of that special red grease made for rubber brake components?

 

[semi-acoustic]

Hi

Thanks again for the replies it is very much appreciated, have new brake fluid at the ready plus red grease.

Regards