Seized (standard) Front Calliper

[jonhill]

I can't push one of the pistons back into the calliper on one of my standard front brakes. How do I free it up?

 

I tried replacing the other three pads and pressing the brake pedal. The stuck piston seemed to come out a touch, but isn't going back in. I'm reluctant to over do this in case it pops right out.

 

I have some Halfords brake cleaner. Is it the right thing to do to spray this onto the piston, or will it damage the seal.

 

Any advice appreciated.

 

Thanks,

 

Jon

[puremalt]

Mine just failed its MOT due to a sticking caliper. £44 for a new one , assuming it's Triumph, made good sense.

I don't think it's worth trying to free it, as you say you may knacker it

 

This one goes up to 11

[Sheds Moderator]

You can free them up but it's a bit sketchy. For a 7 I recommend a rebuilt caliper. Rimmer Bros in Lincoln may do repair kits (Spit mk4) or failing that it's an exchange unit: motor factor, Rimmers etc.

[Normans_Ghost]

Unless it's truly siezed, which I doubt, I would remove the pad from the stuck piston and use 2 large screwdrivers inserted at top and bottom to lever the piston back. Remove the master cylinder cap as the fluid is pumped back into the m/cyl.

 

You may have to use fairly strong leverage and you may also have to do top - bottom sequence to get it to move. When you have moved it get someone to push gently on the pedal so the piston comes out and presses the end of the screwdrivers against the disc. Then lever the piston back in again and repeat the process until it's free. The test is to refit the pad and get someone to push pedal and release. If disc turns without too much friction then it's free.

 

Worst case is you'll have to replace calliper, which you're prepared to do anyway.

 

I have known callipers sieze solid, but only on old cars with a high content of water in the fluid which have been left unused for many months.

 

Norman Verona, 1989 BDR 220bhp, Reg: B16BDR, Mem No 2166, the full story here

You and your seven to The French Blatting Company Limited

[jonhill]

Puremalt,

 

Where did you get your new calliper from?

 

Caterham want £80 + VAT, but more importantly can't deliver until Wednesday now, due to Easter. Apparently, it's off a mk2 spitfire.

 

Jon

 

Edited by - jonhill on 13 Apr 2006 14:18:05

[Tom_C]

Jon

 

try here if it is a Triumph part, I had bits from them when I had a Herald.

 

 

 

Cheers

 

Tom

 

FH54WLX - only the car supports ManU, honest!

 

see here

[jonhill]

Thanks Norman. I haven't tried too hard so far, I thought I get some hints and tips first. I'll go and use a bit more force Is there anything I could use to ease it? Brake cleaner, WD40, anything?

 

My car has stood for several months whist I did my winter rebuild of the back end. Having said that, the other three pads are barely worn, and the one from this side is virtually worn out, so It's probably been like this for a while.

 

Jon

[jonhill]

Well, I thought I was making progress as the piston seemed to be freeing up as my wife pressed the pedal and I wielded the screwdriver. However, it wouldn't go far enough back in to get a new pad in, even with some force. I thought maybe letting it come further out might help, but I let it come right out, and now won't go in at all ☹️

 

All the usual vendors are shutting up shop for Easter, and the sun is shining ☹️ Someone suggested a race team supporting some Seven racing this weekend might be able to help. Anyone know where there's Caterham racing this weekend?

 

Does anyone have a spare front LH standard calliper they can sell?

 

Jon

[Sheds Moderator]

Jon, move fast and a local yellow pages motor factor will do you an exchange spit caliper in 24 hours. Bang it on on Saturday, job done.

 

Now stop typing on here and ring the shop!

[micksmetafors]

I've got spare front you can have. Give me a call on 07968 307611. Gloucestershire

 

Steve

[Rob Walker]

Moss (Bristol)will supply .

[jonhill]

A big thank you to Steve, I've got my calliper now.

 

Cheers,

 

Jon

[john milner]

I've got much the same problem as the original poster. For the last couple of weeks I have had a small squeak from the front right wheel when turning right. I prepared myself to grease the wheel bearings but when on the stands I found the right wheel was binding.

Front inside RH piston out but does not want to go back. The pad friction material is about 50% that of the outside and on the inside the disc is a bit like a deeply grooved vinyl LP. I managed to get the caliper off the car but so far have been unable to get the piston back in. The car has done 63,000+ miles and has Mintex 1144s on the front.

I think my shopping list is two front discs, a set of front pads and at least one caliper. I know the LH caliper is the same age but unless essential to save a few quid I would rather just get the one or is that likely to result in imbalance and/or another set of discs and pads in the next year or two? Anything else needed or a better solution (I'm not going to upgrade)?

The car is a 2003 SV so my belief is I needed to look at Spitfire IV parts for caliper and discs. Is this correct?

Caterham want £245.70 for a caliper.

http://www.caterhamparts.co.uk/product.php?id_product=691

Rimmers want £49 - £81.

http://www.rimmerbros.co.uk/Item--i-GRID005768

Apart from profiteering is there a valid reason for the huge price difference or am I just comparing the wrong parts?

[The_ASH]

I have recent experience of the front caliper conundrum, sorry if this goes on a bit.

At MOT my car was found to have a leaking front seal, partly out of laziness and also wanting the car working instantly I bought one from Caterham with the view that it had some return/refund assurance behind it should any of the older Blatchat stories be visited upon me. Replaced the leaky unit, pads, etc, bled it, all good, used car and checked caliper during the trip only to find fluid everywhere, cleaned, returned home, fluid seemed to be coming from between caliper halves but I couldn't be fully certain, checked torques of through bolts... wrong, tightened, tested car, all apparently good but checked some days later after no further use and again it was swimming with fluid, on close inspection fluid appeared to be coming out of the top 2 through bolts which points to the transfer seal being in some way faulty between the two caliper halves, over next week repeated all checks, cleaned, used car, fluid continued to appear after car being at rest for some time. So got very annoyed, removed caliper, drove to Dartford again the next morning, told the parts guy the story and that I felt I'd payed top dollar for crap, obtained refund.

Return trip took me past the town of Caterham so visited and obtained caliper rebuild kit from Redline £20, I hate working on brakes but after the previous failure of the minimal involvement option anything was worth a go. Stripped caliper without splitting the two halves cleaned the pistons, cylinders, lightly lubed with fresh fluid and proper Girling red grease, reassembled, fitted to car, bled both sides of car, bled again, tested on road, perfect (apart from remaining fluid in bleed nipples making me think I'd failed).

Type of Caliper Girling Type 14 LF

Useful guide here

Redline for parts here

As a contingency plan I obtained transfer seals from the people here ultimately I didn't need them but it felt safer having them to hand.

A further contingency should the above repair have failed was to get both the fronts refurbed by Bigg Red in Worcester here

Thanks also to Mankee on here who provided moral support.

 

edit: reason for vast price difference for OEM part?... I think you've already hit it on the head... let's put up the price of regularly requested parts and make a bit more bunce. It occurred to me that an upgrade kit was only £700ish and you get both calipers, fittings, etc! (but no stock). The standard caliper is rumoured to come from China now, nothing wrong with that as long as quality isn't compromised, Caterham told me they'd had no complaints (obviously) BUT how many complaints would a manufacturer receive if the part had killed the user which this has the potential to do by draining the front brake circuit (the brake reservoir level warning only being truly visible in the dark).

[Jonathan Kay]

Thanks for the saga.

Do we know anyone in the Triumph sports car world to share experiences and concerns?

Jonathan

[john milner]

Thanks. I'll have a closer look at the rebuild kit. I had initially discounted the idea as the money saved might be small for the work involved and have an unsatisfactory result.

A mechanic has told me to only bother with the faulty caliper as imbalance should not be an issue if I replace one.

I may move away from Mintex 1144 pads. Reasons being a lot of dust and questionable insurance. I don't hammer the brakes and do not go on a track so may go for Greenstuff although I still need to clarify the insurance side of these before buying.

[The_ASH]

I too wondered about imbalance but with the new Caterham caliper on the car there was none.

I should have added to my previous post that although that linked guide is good and has all the answers if at any stage you feel uncertain about what you are doing get someone else to at least oversee or do the work for you... the consequences for cutting corners here are not to be ignored!

edit: I should also have added that should you need them Redline do replacement pistons too, depends whether yours are corroded or not, as an upgrade stainless pistons are also available but then you'd have to refurb both the left and right calipers.

edit 2: I think my estimate of £20 for parts might have been a bit inflated and was for 2x rebuild kits (enough for both calipers), banjo bolts and washers so more bits than was actually needed.

[john milner]

The seized piston will not budge my feeling is that it may be slightly angled which may have damaged the bore making a rebuild more likely to fail.

I have ordered a type 14 caliper from James Paddock and a pair of new discs and Ultimax pads from EBC Brakes Direct. I could have gone cheaper or higher spec on the discs and pads but went for a compromise to overcome insurance hassle while getting brand name quality rather than the unknown. Moss-Europe looked like another quite good place to buy from.

[Paul Deslandes]

John

have you tried compressed air or a grease gun to get the piston out?  If you try compressed air, wrap the calliper in a towel as the piston comes out at a rate of knots.  You need to take the calliper off the car (obviously), block the brake pipe entry hole and then force grease or air through the bleed nipple, or variation to suit available bits to block holes.

The other way is to drill and tap a couple of M6 holes through the back of the piston and insert caphead screws to force it out but I'd try the fluid pressure method first as drilling writes off the piston and can damage the back of the calliper bore.  Or just send it to Big Red.

Paul

[john milner]

Paul,

No. I figured that if the hydraulics couldn't push it out any further and I couldn't push it back in with utility pliers it would be better to admit defeat. I dare say it would have come out eventually but then I would be worried about any damage to the bore. For the sake of an extra £40-£50 I should end up with a brand new caliper that lasts a few years.
 

[Paul Deslandes]

very true, and at least you know that there are no hidden problems lurking.

The grease gun method has never failed me yet though and you can exert a lot more pressure than just using the brake pedal.

Paul

[The_ASH]

On one of the many car rebuild shows on TV I noticed a guy using a small bench hand pump for manipulating calipers, looked like it made things very easy but obviously rather ott for rebuilding just one unit at home.

When I took mine apart the pistons got stuck several times so I pushed them back and started again, I did begin to wonder what would happen if I pushed it back and it got stuck there but fortunately it didn't happen, it is a bit of a challenge to bring them out squarely, when in operation I think the pad being in front of the piston helps to keep it square. Also although the bore being smooth is important it's the piston that needs to be perfect as that's what moves through the seal back and forth so needs to be imperfection free. My caliper is a youngster at only 4500 miles and 4.5 years so there was none of the black goop that everyone had predicted would be hiding behind the piston and also no corrosion, I could however see witness marks from the piston manufacture and rapid assembly of the caliper when new :-( A highly priced mediocre quality part in my experience but then that could be said about many things.