Stock Caliper

Anyone know the size of the banjo bolt for the stock Norton caliper.... For some reason I can't locate the information anywhere.

Also, the left side piston seems pretty well frozen inside my caliper (I'm rebuilding it). I tried using some of the techniques mentioned in the Old Britts website, but nothing seems to be working. Any suggestions?

Finally, the caliper pistons appear a bit corroded. Is it worth the extra money to go with new stainless versions, or is it just fine to sand the originals down and re-install?

Thanks in advance for any advice.

Cheers,

wrench

wrench said:

Anyone know the size of the banjo bolt for the stock Norton caliper.... For some reason I can't locate the information anywhere.

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The original fitting would not have been a banjo bolt but a pipe fitting, nevertheless the caliper brake line connection thread size should be 3/8" UNF.

I'm about to rebuild my rear caliper. I bought SS pistons, not sure why, but it seemed like a good idea at the time.

What would I use to lock or seal in the new brake pipe back into the caliper? Locktite or some kind of thread sealer?

Sorry to hijack your thread Wrench.

Back to the original scheduled programming! :wink:

Coco said:

What would I use to lock or seal in the new brake pipe back into the caliper? Locktite or some kind of thread sealer?

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If you are using the same type of tapered seat fitting as original then nothing should really be needed at all to get a good seal.
If it is a banjo fitting then just use new (or annealed) copper banjo washers.

I don't believe that you should use any loctite on the brake line.

With regards to a frozen caliper piston I received good advice on this forum on how to disloge it. It involved using a grease gun loaded with water. It was the only way to apply enough pressure. I was advised against using air pressure tools.

Didn't matter - the caliper bore was too heavily scored to use again.

TT

L.A.B. said:

wrench said:

Anyone know the size of the banjo bolt for the stock Norton caliper.... For some reason I can't locate the information anywhere.

Click to expand...

The original fitting would not have been a banjo bolt but a pipe fitting, nevertheless the caliper brake line connection thread size should be 3/8" UNF.

Click to expand...

Thanks L.A.B. Yeah, I'm altering the stock set-up a little, going with a stainless line and the works. I thought it was probably 3/8" but did not want to order parts without knowing for sure. I also put on a non-stock metric master cylinder (all alloy, looks spiffy when polished up), so I'm mixing and matching here. I love the appearance of the stock caliper --just want to get maximum bite out of it.

Thanks for the help.

Cheers,

wrench

L.A.B. said:

Coco said:

What would I use to lock or seal in the new brake pipe back into the caliper? Locktite or some kind of thread sealer?

Click to expand...

If you are using the same type of tapered seat fitting as original then nothing should really be needed at all to get a good seal.
If it is a banjo fitting then just use new (or annealed) copper banjo washers.

Click to expand...

Yes, it's simply a new stock, rear brake pipe I'm putting on. I figured since everything else will be new, including new stainless rear lines, I figured new brake pipes would be a good idea as well. Call me crazy but I'm also moving to DOT 5 on the rear since my Brembo front system uses it. New brake pipes and SS lnes will be cool, but I have to tatally flush out the rear master cylinder.

I think I bit off a bit more than I can chew with my MKIII. It's like a love/hate relationship.

Thanks L.A.B.

Coco said:

Sorry to hijack your thread Wrench.

Back to the original scheduled programming! :wink:

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Hijack away Coco, no worries at all. It's all good stuff to know either way.

wrench

TT said:

With regards to a frozen caliper piston I received good advice on this forum on how to disloge it. It involved using a grease gun loaded with water. It was the only way to apply enough pressure. I was advised against using air pressure tools.

Didn't matter - the caliper bore was too heavily scored to use again.

TT

Click to expand...

Thanks, TT. I'm hoping that isn't the case with my bore. Only one way to find out. Regarding the grease gun, hmmm. Neat idea. Wondering how one gets an airtight connection with the caliper? And why no air pressure? Just curious.

Thanks again.

wrench

The recommendation to use the grease gun and water was about exerting sufficient pressure. General air pressure tools would not generate enough static force - ie. water does not compress.

You need to lock the caliper in a vice and leave both caliper pistons in place. Use a wood or steel bar wedged into the groove where the disk runs. If possible wedge 2 brake pads agains the good piston to stop it from moving or popping out.

I didn't have any problems getting the grease gun fitting to screw into the caliper - the seal wasn't great, and the water runs out of the gun quickly. It took 2 pumps of the grease gun to move the frozen caliper.

I am not sure if my previous attempts to get the piston out scored the bore or if it was stuck there because or the bore was scored. It makes a good desk pencil holder now.

Let me know how you go..

I have always used an air compressor for a stuck piston. A quick blast usually pops it. If not a final extreme method is to drill the center of the piston and tap it for a bolt and use a slide hammer or puller. If it is that tight, the caliper is probably junk anyway.

As far as stainless pistons, make sure the ones you buy have a chamfered edge. I bought a set a while back that were quite square and would not slide in the bore without slicing the seals.

The brake pipe fitting is not a pipe thread. It is a straight 3/8-24. If fitting a banjo bolt or a threaded adaptor for a stainless brake line, you will likely need to file the top of the opening flat to seal properly with a copper washer (annealed or new).

I have never used Loctite or thread sealant on any brake part except a little thread sealant on the speedbleedersl.

Coco said:

I think I bit off a bit more than I can chew with my MKIII. It's like a love/hate relationship.

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My eyes are loving the Norton, Coco, but my wallet is sure hating it. I'm not even going to tally up my receipts.... Nooooo way. Sure feels good to see it when I walk into the garage, though.

wrench

I managed to dislodge the frozen caliper yesterday. I heated it up and tried to pull the thing out by applying reverse pressure with a set of pliers (needed circlip pliers but didn't have them). Didn't work. Took the grease gun, filled it with water, pumped away. Nada. (I'm sure I wasn't doing it right). Heated it up and tried to blow it out with air. No way. Mounted it on the vice, put a piece of rubber in the thing to protect the threads and, using a pair of needle-nosed pliers, managed to bite onto a small section of it. By pushing upward, gripping ever so hard, I managed to loosen it. Took about 10 minutes of these very small, upward movements, spinning it in the cylinder. The egregious hunk of corroded steel finally gave way. Once I had the culprit in hand, I climbed on the roof of my shop and hurled it into the Ohio River. Okay, so I didn't do that.... felt like it though.

I fully assumed I'd just be mailing the whole caliper to TT -- figured he could have it as a back-up pencil holder in case he needed the extra storage -- but the thing is actually pristine, not a scratch or flaw inside. Even the gaskets were as new (still replacing them).

wrench

TT said:

water does not compress.

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How apropo...Today, I can tell you gasoline doesn't either. Neighbours lawnmower...won't start. Natually he comes to beg so I fill the tank, which is dry. Float needle or float stuck due to couple years of non-use and varnish in bowl. Me thinks I can get the gas which has meanwhile run into the cylinder and out of the little exhaust and all over the ground to clear out of the motor with a pull on the rope. Give the rope a good old Norton kickstart type pull and the piston moves till it suddenly stops dead against the gas in the cylinder, and as I have pulled with all my might, the mower tips up and I pull the handle of the mower...right into my rib.

Jerk...íf I do say so myself. Should have known better. Can hardly breathe now as the nice pain is oh so pleasant.

So...water won't compress, neither will gasoline...but rib cages will... :wink:

Better luck with the caliper!!!

Wrench - glad to hear you got the caliper piston out using yet another technique.

No need to send the caliper to me ... I already have backups.

I was at the beach yesterday when a pristine Norton 850 turned up. It was immaculate. Serious amounts of Colorado Norton components: Brembo brakes (fully floating caliper), chromed fork legs, Viking Black Chrome exhaust, single Mikuni, Corbin seat....

Not one oil leak...

Luckily my basic 850 was in the shed.

hewhoistoolazytologin said:

TT said:

So...water won't compress, neither will gasoline...but rib cages will... :wink:

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OUCH, hewhoistoolazytologin. Funny story. That pretty much is something I'd do on any given day. Good luck with the rib cage! And yes, I got lucky, me thinks, with the caliper. Stainless steel pistons are on their way, too. Next project is - along with new tires and electrics - the forks. I've already got the rebuild kit in hand.

Hope you're feeling better today....

wrench

TT said:

I was at the beach yesterday when a pristine Norton 850 turned up. It was immaculate. Serious amounts of Colorado Norton components: Brembo brakes (fully floating caliper), chromed fork legs, Viking Black Chrome exhaust, single Mikuni, Corbin seat....

Not one oil leak...

Luckily my basic 850 was in the shed.

Click to expand...

I'm sure that "basic" 850 of yours is pretty awesome. My 750 will remain more or less basic, but at least it will be clean for the first time in years (previous owner didn't know how to care for the beast).... won't stay that way, of course. A few good runs on our filthy PA roads will take care of that.

Again, thanks for the help.

wrench