New Brake Pistons or New Brake System?

[Lewis.Dundas]

Does anyone know where I can get replacement pistons for my 78 xs11e? Mine are pitted and they continue to sieze or hinder my front brake performance though they don't leak.

Or I would consider using an after market caliper system like the ones mentioned in a previous thread if I can find them.

All I know is I need better braking up front so any help is appreciated. Also, does anyone have a web or email address or phone number for Merriam Cycles? Someone mentioned they had brakes that would fit?

[RUSH]

see the "links" section for help

[ratbyk]

Improving Brakes

Louis, the front brakes on a 78XS can be made to work just fine.
Service the front calipers with new kits. As you assemble the calipers, after entering the pistons well into the caliper put a smear of lithium white grease all around the final 1/4" or so of the piston. This will keep them free and sliding in and out just fine.
Replace the front brake hoses with braided stainless lines.
Put a kit into the master and bleed it out.
You will be able to lock the front wheel if you get on it to hard.
Stainless lines are available from Randy here on this site or measure up you existing hoses and go to a good Harley shop. They will have an assortment of hoses in stock.
Ken/Sooke

[randy]

Lewis,

Ken's right on the mark. Clean out the calipers paying special attention to the bore and the groove where the square o-ring sits. Be sure to get all the gunk out of that groove or the new seal will leak (don't ask how I know this). I used toothpicks and q-tips so as not to scratch the metal.

You know, although they may be gunky, it may not be the pistons that were seizing. There is a slider (on the single 12mm bolt) that , if it's not lubed will sieze. This slider allows the caliper to relax when the brake is released and acts as an adjusting mechanism as the pads wear. If your outboard pad is wearing more than your inboard, this slider is the culprit.

HTH

[randy]

Sorry,

Forgot to add, if you need new pistons, Mikes XS has them for $24 each. All three are the same size, it's Mikes part #29-0516

[Lewis.Dundas]

Thanks Randy & Ratbyk for the insight.

Didn't think about the caliper slider siezing. I will definitly redo that. I assume white lithium is best?

I will try to contact this Mike XS for new pistons.

Regards,

[randy]

Lewis, order the pistons by the part number. Don't try to order them for an XS11. He'll tell you that he doesn't have them!

His site is devoted to XS650's and he'd rather not take responsibility for cross referencing parts from one model to the other.

Take my word for it, they fit. I've got three of these pistons in my 79F

[TopCatGr58]

Partsnmore also has the pistons available also. Here's the poop on the part numbers, the caliper assembly #'s for both the XS11 and the 650 are the same, so that's why you can use the 650 piston in the XS11 caliper, just don't tell MIKE it's for an XS11.

https://www.partsnmore.com/item_inde...art_unique=566

BRAKE CALIPER PISTON
Fits: Front & Rear, XS1100 (78-81),
Fits: Rear, XS1100L (1980) Midnight Special, XS1100S (79-81) Special.
$29.00 EA. Part#29-0516

https://www.mikesxs.net/mikesxs-chas...ategory_id=1.2

Brake Caliper Piston - Fits: Front or Rear Caliper on 1977-84 650's.
Replace if pitted or scored or air will seep into the brake system.

Part #29-0516 $24.00US EA.

1J3-25810-04-00 78XS650E front caliper assbly

1J3-25810-04-00 78EXS11 front caliper assbly.

[Lewis.Dundas]

Thanks Randy & TC. I ordered them today along with a new Master Cylinder. I figured that Yamaha must have used the same calipers on both bikes otherwise you guys wouldn't have told me to buy them.

I have to say it was a relief to finally find them. I really didn't want to go the modification route trying to make some other brake system work.

You know its been over 4 years since I visited this site. I guess I forgot what a great group of guys and resource you all are.

Regards

[NDAna]

OK on your good advice - just ordered 2 pistons, 2 kits and speed bleeders from MikesXS, for my '80 G. Sure hope they work- will let you know
Sam/NDAna