Seized calipers clean and refurb

Joined
Jul 12, 2016
Messages
5
Location
Castleford, UK
Bike
Honda ST1100Y
For some time now I've been finding the bike a little difficult to push around and last week after a ride it became apparent that it was because the front brakes were binding. No problem, I thought, just need to get some brake cleaner on the pistons and free them up ...... How wrong could I have been !

I dropped the front wheel out thinking I could do the job with the calipers in situ - not a chance. One of the pistons on each caliper was seized solid so the only remedy was to remove the calipers and get them on the workbench.
I managed to get two of the pistons out really easily, the third took an application of WD40 and 10 mins of twisting and pulling, but the last one ........ 3 good applications of WD 40, 30 minutes of soaking time in total and 45 minutes of twisting, pulling & tugging with a pair of mole grips ( thick cloth in the jaws of the grips so as not to damage the piston ) finally saw the piston loose. The body of the piston was very scored, hence the problem I guess. Needless to say, the dust seal was completely knackered so I've taken the precaution of ordering a couple of Caliper Seal Repair Kits and I'm going to overhaul the calipers completely. All 4 pistons are now nice and smooth after polishing them, for what seemed like an age, using very fine wet & dry paper and finishing with chrome polish. I have replaced the calipers on the bike and bled the system then took it for a 10 minute test ride. The brakes are working fine so looks like the oil seals are not badly damaged, if at all, but I'd rather still replace the seals, then I know it's done and I won't have a problem moving forward. We ( some friends and I ) have just planned a trip to France next year so the bike needs to be OK for that.

The frustrating thing about this is that, when I bought the bike in July last year, the dealer from whom I bought it fitted new brake pads to the front as part of the pre delivery "service". I mentioned after the initial test ride that I thought the brakes were binding. When I collected it a week later, the mechanic said they were sticking and that he'd freed them up and all would be good with them. Guess he just freed then enough to get them working although, having said that, I've put a couple of thousand miles on since then with no real issues. They gave me a 3 month warranty with the bike which has expired now obviously but next time I visit the dealer, I am going to mention the problem.I don't think I'll get anything from that ( apart from a little sympathy, if I'm lucky ) but at least they'll know that I'm no mug and that I am fairly savvy about bikes and the workings of them in case I use them again.

Are sticking brakes an issue with the ST1100 ? The bike I have has spent much of its recent life stood in a garage, maybe having 400 miles per year put on it. This, in itself, is never going to be good for a bike and may be the underlying cause for the above .... Can anyone clarify that for me please ?
 
Joined
Feb 25, 2016
Messages
4,759
Location
Northumberland UK
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VStrom 650
Two Job,,,, or is it now Three Job, with bike mechanic being the latest role.
You've hit the nail pretty much on the head. Lack of use and prolonged sit ups don't help.
I've had front and rear issues and the treatment required is exactly what you've done.
A mechanic suggested it would help before and during prolonged periods of little use to kneel next to the bike (and pray-only joking) and with one knee against the caliper body push it in a good way and then pump them back out, do this several times and then do the other side.
It seems to help.
Enjoy your ride to Francais, it's a good place to ride through and the foods not bad either.
Upt'North.
 

ReSTored

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Joined
Nov 6, 2005
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1,472
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Mississauga, Ontario
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2019 Tracer GT
STOC #
4463
I've had no issue, yet, with the front brakes, but I've found the rear brake requires relatively frequent cleaning and it did seize once. I replaced the pistons and the seals. I check and clean the brakes twice per season with one wheel removed at a time .

If you want to remove the piston or clean off as much of it as possible use the brake lever/pedal to pump the piston out to the limit or right out of the caliper. A small piece of plywood about the thickness of the disc and a bit larger than the pads will stop a piston from popping out if the other one is partially seized as they rarely move out at the same rate. The plywood spacer works well on the front as you service the left and right calipers. Cleaning the pistons, the pads, the pad pins and lubing the sliding pins keeps everything working well. If everything is working OK you should be able to push in a piston using finger pressure alone.

Now that you've removed and serviced them periodic cleaning as per above should keep them working properly. I also have Speed Bleeders and change the brake fluid every second year as part of the preventative maintenance process.
 
Joined
Aug 10, 2015
Messages
2,029
Location
Fort Worth, Texas
Bike
91 ST1100/06 ST1300
Stuck pistons can be removed with a grease gun. Replace the bleed port with a zerk fitting if the gun won't snap onto the bleed fitting, hold the unstuck piston (s) in place with a little c-clamp, attach the gun and pump away. I use this method when soaking and gentle coaxing don't work. Almost always, there is severe corrosion around the piston underneath the seal. More modern stainless pistons don't grow this corrosion but can still become stuck. The only downside to using a grease gun is the mess.
On ABS/Linked brakes, plug any extra holes with short bolts of the appropriate thread.
 
Joined
Feb 2, 2009
Messages
2,305
Location
Dahlonega, GA
Bike
2018 NC750X
STOC #
7666
Had a similar experience with my 1100 after it sat for a while... front pistons seized. Firm squeeze of the brake lever finally broke them loose, but I returned to the house and dismantled the calipers immediately. Had to replace two of the pistons because of corrosive scoring. Replace all the seals, cleaned and reassembled. All is well with the world.
 
Joined
Oct 6, 2014
Messages
130
Location
WIGAN, UK
Bike
ST1100, 1998 non abs
Hi Twojobmick,

Ive had my ST for just over 2yrs, I had a brake binding problem about 3 months back, new seals solved the problem, I've got the brake removal down to a fine art as I tend to give them a mini service when I do my oils.

Just remove wheel, drop out pads and press brake lever to force the pistons out a bit , clean/lube and use G clamp to push back in, pads cleaned with wire brush, re assemble with a touch of cooper slip on the contact points.

I find this preventive maintenance helps intervals between new seals, I also use the bike daily which I'm sure helps, laid up bikes can be a pain as things seize up.

This is just what I do, maybe I've got OCD !!!!!!!!!!!:)
 
Joined
May 30, 2007
Messages
1,387
Age
72
Location
Grand Junction, Colo.
Bike
92 ST1100
Stuck pistons can be removed with a grease gun. Replace the bleed port with a zerk fitting if the gun won't snap onto the bleed fitting, hold the unstuck piston (s) in place with a little c-clamp, attach the gun and pump away. I use this method when soaking and gentle coaxing don't work. Almost always, there is severe corrosion around the piston underneath the seal. More modern stainless pistons don't grow this corrosion but can still become stuck. The only downside to using a grease gun is the mess.
On ABS/Linked brakes, plug any extra holes with short bolts of the appropriate thread.
+1!........works every time and keeps unwanted tool marks off of pistons, etc.;).
 
OP
OP
twojobmick
Joined
Jul 12, 2016
Messages
5
Location
Castleford, UK
Bike
Honda ST1100Y
Thanks to everyone for your replies .....Upt'North ... 3 job ! ..... Nice one mate lol

Bike isn't stood much any more, it's history however shows it has been with the last 2 out of 3 ( exc myself ) owners. I use both my bikes regularly, they're my preferred method of transport when possible, so hopefully this issue won't repeat itself once I've overhauled the calipers / seals. Strangely enough, the rear is fine so I'm not going to do anything with that until the next pad or tyre change at which point I'll give it a precautionary clean up.

Done France ( Normandy ) on my 800 Intruder for the last 2 years so I know , the riding is great and the food & cider too !

Roll on end of May !!!

PS - just bought this today..... Great colour match for the ST1100 !

image.jpg
 
Last edited:
Joined
May 30, 2007
Messages
1,387
Age
72
Location
Grand Junction, Colo.
Bike
92 ST1100
Good to hear the front brake issue is resolved!........that IS the main stopping brake used! For now, bleeding the rear brake would at least help removing some of moisture build-up. Problem IMO, is bike was ridden many a time for short distances, then parked for a period of time resulting in calipers/brake pads cooling off, which draws outside moisture to area. Repeat several times, with bike setting for any period of time between riding, along with medium to high humidity, and your finding result will occur;).
 
Joined
Oct 6, 2014
Messages
130
Location
WIGAN, UK
Bike
ST1100, 1998 non abs
I'm off to Normandy this June, battlefield tour, can't wait!!!!.
I did the WW1 sites a couple of years ago, stunning roads, weather, nice folk too.

Enjoy:)
 
Joined
Aug 26, 2013
Messages
115
Location
Dewitt, Michigan
Bike
1997 ST1100
A common experience with bikes of this age. I had exactly the same issues but mine started on the rear brakes. As previously stated, corrosion under the seals swells them into the pistons. One of the rear pistons was so tightly jammed I had to reconnect them to the bike, bleed them out again, put a block of wood under the good piston and use brake pressure to pump out the sticking side. I didn't have a grease-gun. The next year, I had the same problem on the front brakes. Do yourself a favor and do your rear brakes while it's your idea!
 
OP
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twojobmick
Joined
Jul 12, 2016
Messages
5
Location
Castleford, UK
Bike
Honda ST1100Y
Update .... Got the caliper repair kits last week and stripped / refurbished / refitted the front calipers. Old dust seals were absolutely knackered although oil seal seemed not too bad. At least I've been able to clear all the corrosion / dirt build up in the seal grooves and also clean the calipers up properly with a small brass bristled brush and brake cleaner / toothbrush.
I also ordered some wind deflectors for the mirrors when I ordered the seal kits so those were fitted today too. All in all, a good days work !
 
Joined
Oct 6, 2014
Messages
130
Location
WIGAN, UK
Bike
ST1100, 1998 non abs
They are a good job to do on the ST, my old Suzuki V Strom brakes were an absolute ***** to fix, corrosion was the main issue, I had to drill out the calliper to get a drift in to knock out the pin that retains the pads.

Cheers
Chris
 
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twojobmick
Joined
Jul 12, 2016
Messages
5
Location
Castleford, UK
Bike
Honda ST1100Y
Waaaahhhhhh ...... that's a complete ball ache Caddyman !

I did the caliper on my wife's Suzuki VL125 Intruder last year ...... easy as peas .... mind you, it's only a single piston caliper so couldn't be too difficult could it ?!!
 
Joined
Sep 10, 2011
Messages
2,211
Location
West Michigan
Bike
'98 ST1100
STOC #
8470
I have had good luck keeping the calipers from sticking by coating the seals and seal grooves with silicone dielectric grease when rebuilding the calipers. I think the binding is caused by a whitish build-up in the seal grooves that causes the seals to be pushed towards the pistons. The dielectric grease seems to help prevent this from occurring.
 
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