RSTD front brake part number

[revpat]

I just bought a '96 RSTD and only had a short ride home and noticed the front brake was weak/grabby. It was really hard to squeeze with little braking and then it catches and grabs. Not sure what is causing this.

 

I took the right brake off and found one of the pistons (or whatever they are called) stuck. I got it unstuck but had to separate the two sides to get them pressed back in. In doing so I think I lost a tiny o-ring where the fluid flows between the sides.

 

So here's my question:

1) It there suppose to be an o-ring on both holes?

2) If so, does anyone know where to find a part number or where to get one?

 

I'll include a pic. Thanks for any input.

 

Revpat

Edited October 4, 2019 by revpat

[Freebird]

I'm not sure which one you are talking about but here is a parts diagram of the front brake caliper.

 

https://www.partzilla.com/catalog/yamaha/motorcycle/1996/royal-star-tour-classic-xvz13ath/front-brake-caliper

 

Taking another look at your pictures, I don't think the parts diagram shows what your are asking. Hopefully somebody else can chime in. My thought would be that their would only be an O-Ring on one side but I'm not 100% sure.

Edited October 4, 2019 by Freebird

[Marcarl]

If memory serves me correct, the manual states that the two halves are not to be separated, hence there are not part numbers for the o-rings.

Now that you have the caliper at this point you should complete a rebuild. The least tiny little bit of dirt in those pistons can be a life changer for you. Take them right apart, clean them well and blow them totally dry. Install new seals and lube them with brake fluid and only brake fluid. Go to your local vearing supply store and get the proper size neoprene o-ring to install, and yes, you will need 2, one for each passageway. Remember!!!! everything has to be clean, clean, clean.

[BratmanXj]

If memory serves me correct, the manual states that the two halves are not to be separated, hence there are not part numbers for the o-rings.

Now that you have the caliper at this point you should complete a rebuild. The least tiny little bit of dirt in those pistons can be a life changer for you. Take them right apart, clean them well and blow them totally dry. Install new seals and lube them with brake fluid and only brake fluid. Go to your local vearing supply store and get the proper size neoprene o-ring to install, and yes, you will need 2, one for each passageway. Remember!!!! everything has to be clean, clean, clean.

 

All Balls makes rebuild kits that are about $20 a caliper and include the piston seals & crush washers, but does NOT include the o-ring you speak of. If you own a dremmel tool get brass brushes to clean out the piston seal groves and flush-flush-flush with cleaning solution.

 

If you find a lot of corrosion inside the caliper you check to make sure nothing is pitted and could tear a seal or leak. At worst case I have a set of calipers in my spare parts bin if yours are in bad shape.

[revpat]

Thanks for the input guys. I ended up buying a used complete caliper off ebay and installed it and finally got it filled with fluid today. Pretty big deal and I'm not sure the calipers are the problem as the brake handle itself still sticks. So now I'm off to figure that one out.