brake disc don't fit with new brake pads

Hi marp,
try looking down two spaces from the caliper puller.
External long reach snap ring pliers for servicing front brake m/c #35 0009.
Looks just like the biltema pliers in your link.
Seems Mikes no longer stocks the angled pliers I was whining about.
 
Yes, Mike's stopped carrying those angled snap ring pliers a couple years back. Fred, I think you may have gotten a bum pair. The ones I got have worked very well for me. They are also perfect for removing the snap ring that retains the slide needle assembly in the '78-'79 BS38 carbs. Some of the classic Honda parts places still carry them .....

http://www.ebay.co.uk/itm/Right-Ang...808995?hash=item2eea625723:g:eIEAAOSwa-dWks4g
 
Does anyone know the exact original dimensions of the rubber seals for the calipers? It's kind of hard to measure them exactly correct. I was thinking of asking a Swedish company specialized in rubber seals. And has anyone tried using rubber o-rings instead of these square profiled seals? Also, which kind of rubber would it be?
 
Last edited:
Thanks.

I have now managed to remove the snap ring, but can't get the m/c piston out. Tried the recommendation in a thread to use a wood dowel rod, but it's completely stuck. Any more tip, dont want to risk destroying anything getting this far?
 
Hi marp,
did you just push on the dowel when you shoved it down the banjo bolt hole or did you whack on it?
Try whacking harder. Then switch to a 5 or 6mm steel rod and whack that.
It's no good as it is, right?
 
Hahah... no no good as is... Just thought I might have missed something

Actually I used a wooden pen, you know the old style 5 mm, and wacked it a bit. The wood started to crack. Will try a steel rod tomorrow (night here now). Thanks.

What can cause it to get stuck that much, the aluminium oxide?
 
will it push back the other way? looks like some rust in the bore out by the seal in your pic above. did the steel washer come out?

you can see the washer sitting on the piston in this pic, my guess is that washer is still stuck in there.

mc guts.jpg


mc guts.jpg
 
Didn't know there was a washer. No one in the image in the Clymer manual. Maybe the washer is stuck against the bore wall, then. But shouldn't it come loose rather easily when tapping on the piston, since the corroded area is rather small? I have put some more wd40 in the bore, so I will try tapping again tomorrow.

And yes, the piston can be pressed in the other way.

Btw, on the rubber cap, is it some sort of white plastic washer on it? At the root.
 
straight up that's the guts of a later MC 79 standard to be precise. I couldn't find my 73 MC blow up. yes that is a nylon sleeve but again it may be late model only part. the washer sits against a step down in the bore.
 
If you destroy any of it while taking it apart and you need components to rebuild it I have a master cylinder from a 76'C that I have apart for rebuilding. It is in very good condition minus the rubber cap on the very outer end. I purchased another one from a forum member that included extra brake parts I needed.
You are welcome to it for the price of shipping. Private message me if you need it. Mike Stenseth
 
I would take a pick or awl and scrape around the junction between the wall and washer a time or two and dab more rust buster there.
 
Got the piston out. Had to use a steel rod. The washer was rusty. The piston also rather dirty, but the vital parts look okej. What about the rubber part mounted in the middle of the piston? Seems like a good idea to clean under it. Is it supposed to be removed to clean beneath or better to let be so I will not risk destroying it?
 
I tend to leave it on and just work it around a bit to get the gunk out. It's a big stretch to remove it.
 
Okej, then I leave it. You said earlier that you put some brake fluid on the caliper pistons before mounting. What about brake caliper grease? Better, not necessary or bad?
 
I think bad? caliper grease for slider pins? The early calipers don't have pins. Maybe a VERY light smearing in the piston cavities to hold back rust....
 
Hi marp,
It's your decision but I'd carefully take the seal off to clean it and the mandrel separately.
A good seal will survive careful removal and replacement undamaged.
A bad seal will break and it's best that happens with the m/c on the bench rather than on the road.
Brake fluid or o-ring lubricant are the only things to be used when assembling rubber parts.
Caliper grease is only meant for a caliper's metal parts.
 
I'll get by with using only the brake fluid as a lubricant, then.

Another question about which brake fluid to use. The manual says DOT 3, but wouldn't DOT 4 or DOT 5.1 be okej to use as well in these systems?

Interesting reading, weekendrider. Will probably lubricate better and stay on the parts longer. But will it not interfere with the brake fluid and may go into the brake fluid system? I have some silicone grease. Seems that it would work too.
 
Stolen from the website.

Here is a comprehensive list of RRG properties:

Fully compatible with natural and synthetic rubbers
Compatible with brake fluids and some hydraulic oils.
Rust inhibitor (protects from oxidation and rust).
RRG is water resistant.
Hight temperarure. The grease can be used in applications with temperatures up to 210-230F. It will not melt and will not contaminate brake pads.
Petrol resistant. Although it will get contaminated in contact with gasoline, but still it will protect rubber parts from it.
High chemical and structural(mechanical) stability.
High resistance against water washing (will stay on after a rain, or car wash).
Has high wear protecting quality.

DOT3 or 4 will work.
 

Similar threads

A
Width of brake "pad track" or "swept area" on the 72-76 models
Replies
1
Views
262
gggGary
gggGary
gentlemanjim
Help with front end swap
Replies
9
Views
308
gentlemanjim
gentlemanjim
A
The latest and greatest (and stupid expensive) in lightweight components
Replies
2
Views
649
arcticXS
A
X
77/72 XS650 Disc to Drum ?
Replies
3
Views
718
xs650-4-me
X
B
My dead XS650
2
Replies
21
Views
1K
650Skull
650Skull
Back
Top