freeing off calipers after long dry storage

freeing off calipers after long dry storage

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Discussion

Count Vampirski

Original Poster:

151 posts

107 months

Sunday 19th April 2015
quotequote all
any advice on this wood be useful please, particularly the high melt point special lube for coating pistons

4.3 possibly original brakes with 20k dry miles then stored for several years - the brakes now require far too much pressure to get retardation, i am assuming the pistons have become v stiff and need freeing, being mechanically inexperienced, i am not sure how to get them ready for MOT and use - assume pads to have plenty of material left and discs excellent and not rusted or pitted

Colin RedGriff

2,525 posts

256 months

Sunday 19th April 2015
quotequote all
If the pistons are not moving freely then they need inspecting/overhauling by a specialist, or replacing. It's not worth risking it with brakes especially if you aren't mechanically experienced.

Have you checked that the servo is working correctly? Hopefully it will be something as simple as the vacuum hose collapsing or leaking. If the servo is rusted/broken then you will need to replace it and that is a bugger of a job and replacements are not cheap.

Count Vampirski

Original Poster:

151 posts

107 months

Sunday 19th April 2015
quotequote all
Hi Colin, hadnt thought of that - symptoms from memory would fit...
as car is in excellent condition with 20k dry miles i am hoping servo is ok - how do i check it is performing and how do i check for leaks (that would give poor idle though i imagine)

when i did have car on road, it used to grab n/s rear brake and lock under last min braking too

i would like to have braided flexis too due to barn mice - any downsides?

Hoover.

5,988 posts

241 months

Sunday 19th April 2015
quotequote all
fitting braided hoses is consider an upgrade to factory OEM, and there is now downside apart from better braking smile

Colin RedGriff

2,525 posts

256 months

Sunday 19th April 2015
quotequote all
Count Vampirski said:
Hi Colin, hadnt thought of that - symptoms from memory would fit...
as car is in excellent condition with 20k dry miles i am hoping servo is ok - how do i check it is performing and how do i check for leaks (that would give poor idle though i imagine)

when i did have car on road, it used to grab n/s rear brake and lock under last min braking too

i would like to have braided flexis too due to barn mice - any downsides?
If the vacuum hose is leaking then yes I would expect it to run badly. I don't know any specific tests for the servo but I'm sure if you google it there will be a few options. The basic operation is the same regardless of the car.

Krikkit

26,500 posts

180 months

Sunday 19th April 2015
quotequote all
If it's been laid up for many years it sounds like the pistons/sliders have started to bind up in the calipers. It'll also need a complete brake fluid change if it hasn't had one already.

Count Vampirski

Original Poster:

151 posts

107 months

Sunday 19th April 2015
quotequote all
Hi Krikkit, that was my original thinking (will check servo tomorrow using Google test methods)
Are service kits available for the 4.3 oem calipers? - discs and calipers only done 20k miles so should be fine

Steve_D

13,737 posts

257 months

Monday 20th April 2015
quotequote all
To test the servo get the engine warm so it starts reliably.

Turn off engine and press the brakes several times to use up any vacuum still in the system.

Press on the brake with light to medium pressure and hold the pedal there whilst you start the engine. As the engine starts you should feel the pedal pull down as the vacuum builds.

Steve

Count Vampirski

Original Poster:

151 posts

107 months

Monday 20th April 2015
quotequote all
yes thanks will try that

andy43

9,548 posts

253 months

Monday 20th April 2015
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ears Barn find 4.3 with only 20k on it? That sounds interesting. Any pics?

Count Vampirski

Original Poster:

151 posts

107 months

Monday 20th April 2015
quotequote all
..hmmmm, 'barn find?!' - I hadnt misplaced it!! wink