Log in

View Full Version : Front brake caliper overhaul.


Danny Dickinson
27-08-12, 10:05 AM
So, i ordered some SS brake lines because my brakes were nowhere near as good as they should be, and thought it would be a reasonably cheap fix.

However, things have gone from bad, to worse, to damn right bloody awful.

It had a full service inc. valve clearances last month, and was advised that i need new dust seals in the calipers, because there was none haha, so i ordered a seal kit while i was at it to save paying the mechanic to do what i was told on here was an easy enough job.

Upon taking the pads out the calipers, started pumping the lever to push the pistons out, and one, yes, ONE piston moved, then popped out, followed by the fluid. Though to myself right, not an issue, time for some compressed air..... didnt budge them. Being lost at this point, i ventured over to A.T Whites, 30 seconds up the road, and asked if they would have a pop with their compressor, as i figured it would have a bit more whack behind it than my neighbours.... again, nothing. Eventually, after 40mins of not being able to move them, out came the plumbers grips, and after a lot of wrestling and another hour passed, the remining 3 pistons were out.

So, now i have ordered new pistons from suzuki, which come with seals, meaning i wasted money with the new seal set. ARGH!!!!!!!!

Next to order, was new brake pads, seeing as the ones in there are worn all wonky. Now all i have to do is spend what seems like forever cleaning theses bloody calipers and getting it all back together again when i pick up the new pistons from suzuki in lincoln on wednesday.

Costs:
Wezmoto SS brake lines - £39.99
Wurth 500ml braake fluid - £4.99
New seal kit - £44.99
New pistons and more bloody seals - £98.99
Goldfren HH brake pads - £22.98

Is it just me or when it was serviced, shouldn't this have been picked up on??????

And i am now wondering why i didnt just buy new calipers!!!!!

Anyway rant over, i will get some pics on when i get round to taking them.

yorkie_chris
27-08-12, 11:42 AM
A lot of mechanics seem very lassaiz faire about caliper overhauls, IME it's one of the most common and important job.
Maybe a reflection on many bikes on the road doing less miles, I'm not sure.


Re. one piston popping out, what did you expect both of them to come out nice and easy of their own accord?

Next time, no need for compressor, or butchering them with stillsons. Put G clamp on one piston, pump it out a bit, swap to other piston. Just get them to move nice and slow 1 at a time then you get both out easily.

Sid Squid
27-08-12, 11:48 AM
Like Chris says, pump one piston 'til it's nearly out, restrain, pump another, repeat.
When they're all very nearly out of the seals, rock them back and forth and you'll be able to remove them with your fingers, no butchering of pistons needed.

Bibio
27-08-12, 12:29 PM
my preferred method.

one of these http://www.ebay.co.uk/itm/5-PCS-Inner-Bearing-Puller-Set-Kit-Remover-Blind-Internal-Slide-Hammer-New-/380463196554?pt=UK_Hand_Tools_Equipment&hash=item58955fa98a

6 chunky orings to fit on ends of pullers

quick, easy and mark free piston removal with the added benefit that you can pull wheel bearings out with the same tool. may seem pricey but when you do need to use it you will be glad you have it and it will last you a lifetime.

Danny Dickinson
27-08-12, 12:56 PM
Hi guys. Cheers for the ideas, definately lessons learnt for the next time. In all fairness to my stupidity, i do wonder if they would have come out anyway. The top bit of the pistons, as in the bits pushing on the pads, all look like they have been had at with pliers in their time, and when i started cleaning the calipers out, they were like bloody salt shakers!

Also, there was quite a bit of what can only be described as black paste in the bottom of the caliper bore under the pistons. Even though i am putting new brake lines on, would it be worth flushing the whole system first to make sure that any crap is pushed out? There was a little bit in the resevoir too.

Cheers

andrewsmith
27-08-12, 01:49 PM
the G clamp method works.
I've also found a footpump with an airbed adapter works quite well if in a rush.

yorkie_chris
27-08-12, 01:57 PM
Hi guys. Cheers for the ideas, definately lessons learnt for the next time. In all fairness to my stupidity, i do wonder if they would have come out anyway. The top bit of the pistons, as in the bits pushing on the pads, all look like they have been had at with pliers in their time, and when i started cleaning the calipers out, they were like bloody salt shakers!

Also, there was quite a bit of what can only be described as black paste in the bottom of the caliper bore under the pistons. Even though i am putting new brake lines on, would it be worth flushing the whole system first to make sure that any crap is pushed out? There was a little bit in the resevoir too.

Cheers

If you have new lines, clean inside calipers, then yeah you can let some fresh fluid drip through master if you want, probably not much in it.

Clean crap out of seal grooves, this is what makes tham drag

the G clamp method works.
I've also found a footpump with an airbed adapter works quite well if in a rush.

muzikill
27-08-12, 02:01 PM
http://forums.sv650.org/showthread.php?t=173416

Check the before & after pics & make your mind up!

sv_rory
27-08-12, 03:26 PM
I use heat from a heat gun because the seals go soft and the pots lift straight out in seconds

Danny Dickinson
27-08-12, 04:15 PM
http://forums.sv650.org/showthread.php?t=173416

Check the before & after pics & make your mind up!

Just a little bit of a difference aint there ;)

Spent the afternoon cleaning mine up ready for new pistons on wednesday, there was an offensive amount of s**t where the seal sit, but its all out now :)

The calipers themselves are somewhat untidy, as in the paint on them, but to be honest, thats just cosmetic and can hang on for a while.

Thanks for all your replies fellas

Thunderace
27-08-12, 05:42 PM
my preferred method.

one of these http://www.ebay.co.uk/itm/5-PCS-Inner-Bearing-Puller-Set-Kit-Remover-Blind-Internal-Slide-Hammer-New-/380463196554?pt=UK_Hand_Tools_Equipment&hash=item58955fa98a

6 chunky orings to fit on ends of pullers

quick, easy and mark free piston removal with the added benefit that you can pull wheel bearings out with the same tool. may seem pricey but when you do need to use it you will be glad you have it and it will last you a lifetime.

I always use a G clamp, but that is an inspired idea, may give that a go next time, brownie points in abundance to you Sir!:)

Bibio
27-08-12, 05:55 PM
to give you and idea of what i'm on about

http://i48.tinypic.com/2ufqe83.jpg

speedyandypandy
27-08-12, 07:47 PM
tool......me wants one, no postage to Norway, don't like sellers that don't want to make money...

trail guru
29-08-12, 12:21 PM
I use a couple of bits of 6mm plywood, about 40x90mm, and pop one in each calliper in place of the brake pads then pump the cylinders out. When all the cylinders butt up against the ply remove the ply and the cylinders will wiggle out with No1 forefinger and thumb.

Said bits of ply are also useful for padding the calliper housing and cylinders if you need to push them in a bit with a G-clamp or pipe wrench. The ply's a cheap tool but not much use for pulling bearings :-)

Although using a pipe wrench to help remove a stuck cylinder carries a high risk of marking its surface you can 'pad' the cylinder with inner tube rubber (or similar), together with a wrap of gaffer tape around the jaws of the wrench, to reduce the risk of a 'metal-on-metal' accident. Then gently rotate the stuck cylinder to free it.

Sid Squid
29-08-12, 05:03 PM
The plywood trick, (mine's a bit of MDF ;)), is by far the best way of removing the pistons.

There's nothing wrong with using a slide hammer*, but it's simply overkill, there's several hundred PSI of piston shifting force available just by pulling the lever, with absolutely no chance of damaging anything and nothing to buy.


*Very useful tool for many jobs - I mostly use it for bearings.

Danny Dickinson
30-08-12, 02:32 PM
Right, its all together, new pads, fresh fluid and lines etc....

Took it for a test ride to market rasen and back (about 40 miles there and back), but on the way back, it started to feel odd. The best way i can describe it is that when you try to counter-steer, to lean obviously, the bars just want to turn against you, and it makes cornering bloody difficult. I can't for the life of me think what it is doing it.... any ideas? Its worse at lower speeds, sort of 30mph and under.

At first, i thought it might be the new brake lines getting tangled round something, but they are totally free to move on full lock either way...

AkiraSV
30-08-12, 03:43 PM
Are the brakes binding at all?

muzikill
30-08-12, 03:44 PM
Was it like this before the overhaul? Have you been mucking about with the back wheel alignement?. Do you hear any rubbing from the front?

When its stationary does the full lock side to side on the steering feel ok?

Danny Dickinson
30-08-12, 03:48 PM
No it wasnt like it before the overhaul, i havent touched the rear wheel in anyway, or anything associated to it, and i cant hear any rubbing at all from the front that would suggest the pads are rubbing/sticking.

And yeah, the full lock feels fine.

Im confused =(

yorkie_chris
30-08-12, 03:48 PM
Too much fluid in reservoir causing drag when warm?

Danny Dickinson
30-08-12, 03:59 PM
Fluid level is between upper and lower. Would it be worth taking a little out to see if it makes a difference?

Although it was fine for the first 30 ish miles of the test ride. The biggest difference being that i have the ability to stop now compared to before, ha!

speedyandypandy
30-08-12, 05:26 PM
How fresh was the brake fluid, unopened bottle or bottle been sat on the shelf for ages?

Danny Dickinson
30-08-12, 05:51 PM
It was a fresh bottle. Its wurth DOT4 stuff.

If anybody local fancies riding it themselves then they can, to get an idea of what im on about......

Danny Dickinson
30-08-12, 06:15 PM
So people know, i am starting a new thread for this, seeing as its a new problem.

Thanks guys

mackemforever
31-08-12, 11:16 AM
Like Chris says, pump one piston 'til it's nearly out, restrain, pump another, repeat.
When they're all very nearly out of the seals, rock them back and forth and you'll be able to remove them with your fingers, no butchering of pistons needed.

Easiest way is surely just to use what you already have to hand when you're doing this job.

By that I mean simply put your brake pads infront of the pistons, they are thick enough to ensure that none of the pistons can be pumped out, and once all four are up against the brake pads, remove one pad and repeat, and by that stage they should all be right one the verge of coming out.

It's what I've always done, saves having to go and get any other tools.