[pip]

Brake problem with \'96 750

I use my '96 gsxr750 to get to and from work in all weathers all year round. I found most winters to cause all the brake calipers to seize meaning a strip down clean and new seals to be required.
I have just replaced all the seals on the front calipers and also replaced the front discs and pads also due to the buttons on the disc becoming loose. I have bled the system MANY times the conventional way but the lever still felt spongy. I then bought one of those vacuum bleeder kits and ran a whole bottle of fluid through the calipers with exactly the same result.
The brakes seem to work o.k., i.e they will stop the bike, but i can pull the lever all the way back to the handlebar. If i leave a tie-wrap on the brake lever overnight then it will stiffen up, but doesn't usually last that long.
Is it possible that i have fitted one of the seals incorrectly, would it cause this type of problem?
I fully cleaned all the pistons and caliper grooves with the proper cleaning fluid, the pistons looked a little scored but not badly.

Help???

Pip

 

[audi1031]

Re: Brake problem with \'96 750

It could be that your surface on where you tighten up the hose to caliper is not smooth or is not sealing? also are you using the same washer for the seal? try a new one if not. One other thing on the brake lever there is a roundish button that has numbers on it try to change that around you have to push the lever forward then put on another number and check it see if that would help

 

[GSXR-Freak]

Re: Brake problem with \'96 750

Also if you are on stock lines, you might want to think about SS lines.. As lines get old they do not work as well.

John

 

[ssallber]

Re: Brake problem with \'96 750

Sounds like a leak in the system somewhere. I suggest replacing all the sealing washers on the brake lines. You may have a leaking break line also. If they are Kevlar and old, replace them. If they are stainless, look carefully around the swedges, where the lines attach to the fittings. Past experience I have had is Kevlar lines going bad, worn sealing washer, and a brake line that had a very small leak near the fitting due to movement of the line over time working the swedge joint. Last summer I had to buy a master cylinder rebuild kit for my 96 GSXR which brought my brakes back to race shape.

 

[pip]

Re: Brake problem with \'96 750

Thanks for the replies guys,

I have had goodridge SS hoses fitted for about a year now and where fine until after the caliper strip down.

I did use the same crush washers but i can see no evidence of leakage from anywhere along the lines, fittings or master cylinder.

I have the lever adjuster set to 1 which i beleive is it's furthest out position.

Could the SS hoses be twisted internally, and if so would it cause this problem. I say this as i had to twist the fittings on the RHS caliper to get them to line up, but i had to do this when i first fitted the lines aswell and they worked o.k.

I also found it difficult to determine which way to fit the oil seals in the calipers. They are supposed to have a slightly tapered edge, but they looked perfectly flat even when stood on a flat surface. Could this cause the problem if they are the wrong way round or would it just make the pistons stick?

Looks like i will have to strip everything down again and look for any problems....bloody hell.

Pip

 

[Mr.Gixer]

Re: Brake problem with \'96 750

The problem is your master cylinder/seals. Now that you have serviced the calipers, the pistons will move alot more freely and if the master cylinder seals are worn and swollen then when you release the brake, the returning lever will actually pull the pistons back a little. When this happens the first bit of movement of the lever is taken up in getting the pads up to the disks, so you will always have alot of lever movement. This didn't happen before because the pistons were too tight for this to happen. This is exactly the same problem my friend had with his 11 and only a new master cylinder cured it (his bike is alot older)

Good luck!

Phil

 

[ssallber]

Re: Brake problem with \'96 750

I agree with Mr. Gixxer. You need to buy the master cylinder rebuild kit. It is not very expensive and easy to install. The symtom I had was the lever did not want to extend back out once compressed or moved very slowly. Like Nike says "do it" and you will be free!