ABS brake caliper please help.

Tricci1009

Joined
Sep 15, 2024
Messages
2
Age
34
Location
Thompson CT
Bike
1999 St1100a
I got another ST1100 it's a 1999 with ABS well the rear brakes weren't working and I was told it needed a master cylinder. I replaced it and found that the caliper is bad I can't bleed it. Can't get any fluid out of it. It has two bleed screws I can't for the life of me find a replacement online they are all non ABS. Even ones that say they are abs are not the right one. Does anyone know where I could get a rear caliper that has the linked brakes and two bleed screws?
 
No, I don't know where you can find your caliper, but sooner or later one will come up on ebay. That said, I know you don't want to wait for it. Here are two mc recyclers. Once upon a time we called them junk yards and they let customers roam and remove parts, bring them to the counter, and pay for them. Alas, they have gone upscale, which makes it easier. Give them a call and ask. You have nothing to lose.

Greentown Motorcycle Salvage, 2365 State Street, Uniontown, OH 44685
330 499-9768

Pinwall Cycle Parts, 635 3rd Street NW, Massillon, OH 44647
330 879-9910

IIRC, there was another such place out west - Colorado maybe? Try a google search. Used auto parts places plug into a nationwide network. I don't know if there is a comparable system for mc parts. Ask the places I listed.

Good luck.
 
Thank you I will try that. I do however see the rebuild kits for it. I've never rebuilt a caliper before but I'm good with stuff like that so it's something I might look into.
 
Tricci1009 said:
Thank you I will try that. I do however see the rebuild kits for it. I've never rebuilt a caliper before but I'm good with stuff like that so it's something I might look into.
Click to expand...
If you can rebuild it, that's probably your cheaper option.
Unless the pistons are terribly corroded, that should work fine.
Any brake fluid when you remove any of the brake lines?
 
Welcome to the forum.

Please do not buy parts as a method of troubleshooting.

You need a shop manual if you're going to do your own work.

ABS brakes require a very specific bleeding procedure.
 
Al st1100 said:
If you open the bleeder and no fluid comes out replacing the caliper won't help.
Click to expand...
It will if the obstruction is in the caliper, but that still isn't a good trouble shooting method.

Try removing the bleeder screw completely and see what happens. Maybe you'll get lucky and the bleeder screw is blocked.
 
If you’re only trying one of the bleeders while depressing the brake pedal, you should know that you may need to try the other one. The rear caliper is activated by both the pedal and the secondary master cylinder on the lower left fork leg. The two cylinders activate different pistons/circuits in the caliper. It’s possible you opened the wrong bleeder for the pedal circuit.
 
Andrew Shadow said:
It will if the obstruction is in the caliper, but that still isn't a good trouble shooting method.

Try removing the bleeder screw completely and see what happens. Maybe you'll get lucky and the bleeder screw is blocked.
Click to expand...
there's a lot of "if" here
 
wjbertrand said:
If you’re only trying one of the bleeders while depressing the brake pedal, you should know that you may need to try the other one. The rear caliper is activated by both the pedal and the secondary master cylinder on the lower left fork leg. The two cylinders activate different pistons/circuits in the caliper. It’s possible you opened the wrong bleeder for the pedal circuit.
Click to expand...

[edited - I failed to notice that this was the 1100. The 1100 does not have a bleed valve near the pcv that I ever found]

When in the garage, stationary, the rear brake pedal will operate all three calipers.
The same master cylinder has two lines attached to it.

The shortest one goes direct to the rear centre piston - the forward bleed valve.
The other line goes through a number of components, eventually ending up at the two outer pistons - the rear most bleed valve.

Press the brake pedal. it should offer resistance with very little movement

Open the bleed valve for the rear centre piston - the forward bleed valve on the rear caliper. Apply the rear pedal. Fluid should expel easily, an the pedal will move easily as it pumps out fluid. That is the short line checked

Now for the long line. If you are not getting fluid out of the rear most bleed valve on the rear caliper, then it is necessary to check how far the fluid is getting. So in this order (The steps assume you will have a bleed tube fitted, that you dont let any air in, and you close the valve after checking that fluid is flowing.

Open the bleed valve for the front right centre piston, the lower valve on the front right caliper. Fluid should flow easily when the brake pedal is pressed. No resistance at the pedal.
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Open the bleed valve for the front left centre piston, the lower valve on the front left caliper. Fluid should flow easily when the brake pedal is pressed. No resistance at the pedal.


Check the rear caliper, rear most bleed valve again.




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If you cant pin it down to a particular line, then its time to crack open the banjo bolts on the calipers. Weight the pedal, crack open the bolt, see if fluid seeps out. Close it up again. For the SMC, check the outlet banjo.

This should tell you whether or not fluid is getting into the caliper (or out of the SMC)

All of the time you are trying to establish if there is a blockage and then find out where it is. So you dont do all of these tests - just the ones that give you more information. For example, if fluid isn't coming out of the rear caliper bleed valve outer piston), but you know it is getting to the banjo bolt - then there is a blockage somewhere in the caliper itself.


When you have finished messing around, you have to make sure that your braking system is safe. Personally, if I havecracked open a banjo bolt, I will replace both washers before I ride the bike. Maybe that is overkill, but I like to be safe.
 
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Andrew Shadow said:
It will if the obstruction is in the caliper, but that still isn't a good trouble shooting method.

Try removing the bleeder screw completely and see what happens. Maybe you'll get lucky and the bleeder screw is blocked.
Click to expand...
Engage both brakes at the same time and see if that helps. Not sure about 1100 but brakes are linked on ST1300.
 
I just edited my post above.

Forgot (again) that this was the 1100. The 1100 doesn't have a pcv bleed valve. Otherwise the abs/cbs brake line arrangement (with 3 piston calipers) is the same as on the 1300 - but you do need to check the mechanical linkage between the SMC, fork leg and caliper bracket - behind the grey plastic shield. It has needle roller bearings and it needs to be able to move smoothly. Mine was a rusted, gunged up mess when I discovered that it was there. It was locked up solid, but it cleaned up nicely. The grease in the roller bearings was stiff, but the needles were clean, so they were easy to make operational again.
 
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