Front Caliper Rebuild

All 3 bikes get the flush once a year ... after re-building the Commando front brake , the other 2 have 3 calipers each and honestly don’t like the thought of having to re-build ‘em all , if they were bad as the Norton’s , learned my lesson

Parts will hopefully be here on Thursday. It won’t take long to put things back together.

swooshdave said:

It spend a bit of time in the ultrasonic cleaner with heat and the caliper looks probably better than when new. I've got a few days until the order from Old Britts shows up so I'll find some other projects to work on in the meantime. Because you know there's always other things that need tending to...

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Is the surface texture of your caliper a result of the ultrasonic cleaning or is that normal? The ones I have are much smoother on the outside surfaces. Maybe they were polished by P.O.

NickZ said:

Is the surface texture of your caliper a result of the ultrasonic cleaning or is that normal? The ones I have are much smoother on the outside surfaces. Maybe they were polished by P.O.

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Yours has been polished. Some surfaces are rough cast, some are smooth enough to be polished.

I don't know what Lockheed did to finish the surface but it wasn't much.

I'm using Silicone DOT-5 brake fluid from NAPA. They actually sell quite a lot of it. I don't know why it gets a bad rap from people. Works great for me and looks the same as when it went in after 3 or 4 years of use.

motorson said:

I'm using Silicone DOT-5 brake fluid from NAPA. They actually sell quite a lot of it. I don't know why it gets a bad rap from people. Works great for me and looks the same as when it went in after 3 or 4 years of use.

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Is it 5 or 5.1?

The challenges with 5 is you have to have a completely clean system as an glycol contamination is BAD. There are also some rubber components that may not be compatible. Then again some people luck out. Others do not,

Yes , I think I may using it too , whatever Matt recommends in his M/C upgrade ..... think maybe that it without looking ...

motorson said:

I'm using Silicone DOT-5 brake fluid from NAPA. They actually sell quite a lot of it. I don't know why it gets a bad rap from people. Works great for me and looks the same as when it went in after 3 or 4 years of use.

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swooshdave said:

Is it 5 or 5.1?

The challenges with 5 is you have to have a completely clean system as an glycol contamination is BAD. There are also some rubber components that may not be compatible. Then again some people luck out. Others do not,

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I do use dot 5 in anything I care about. I bought a gallon jug in the mid 70's, still have plenty left. Besides my nortons with discs. Example: my Lotus Elan+2 The braking system is practically unobtanium. While the fronts are the same as triumph TR6/GT6 The rear are unobtanium used ebay may run a few grand each side, then the master cylinder and 2 pneumatic/hydraulic servos . Only the entire brake system costs close to a restored norton commando. When I parked the car in 95 it had dot5...the brakes still work just fine today.

The crud SD is scraping is corroded aluminum powder that is what makes the impressions in the orings. Dot 3 like E-10 sucks up water then causes aluminum corrosion. Most calipers have dust(water) boots, the norton/lockheed calipers DO NOT. If you ever run in the wet the calipers will corrode
A stainless piston is ok. Theoretically it is totally supported by the oring and should not touch the aluminum caliper at all.... even rain water will eventually cause galvanic corrosion.
How ever I would never use a stainless cap or bleeder unless thoroughly coated with tefgel paste. I reuse my steel ones. If you bleed the brakes ...how do you get the residual fluid out of the bleeder? It is open the the atmosphere where the humidity is.
Original calipers were buffed and polished especially on the ribs and outward body and "usually" sanded and polished between the ribs. Never glass bead finish from the factory.

motorson said:

I'm using Silicone DOT-5 brake fluid from NAPA. They actually sell quite a lot of it. I don't know why it gets a bad rap from people. Works great for me and looks the same as when it went in after 3 or 4 years of use.

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When Dot 5 first appeared, it had higher temp ratings then Dot 3 or Dot 4.
That is no longer the case today.
The best Dot 4 brake fluids have higher temp ratings.
You may know already Dot 5 does NOT absorb water, so if it gets in the brake system, as it usually does, it creates 2 problems.
First, Water boils at a low temp, causing the brakes to feel mushy.
Second, since the water is not absorbed, Dot 5 is not hydroscopic as are dot 3 and 4, the water that does get in can corrode wherever is has ended up.
The last big issue is if there is any Dot 3 or 4 left in the system, the two fluids are not compatible, they mix together and a gel is formed.

In case others do not know Dot 3, 4 and 5.1 are glycol based Dot 5 is silicon based.
Dot 5.1 is used in ABS systems, as it is a thinner fluid, than Dot 3 or 4, and gets thru the very small valves that make the ABS work, faster. It is not needed for non ABS systems.

Parts got here today. Ordered I think Sunday night. Note the new Andover Norton packaging in paper bags. Nice job @ZFD! The item in the paper bag is a new hardline that connects the hose to the caliper. While the old one was serviceable I just wanted to freshen up that part of the bike.

Rebuild done. Tried to bleed using the Mityvac and that got me nowhere. Going to try the syringe method and push fluid up today. I did make an assembly video that I'll put together one of these days.

if you bleed the master cylinder first, it will be a lot easier to bleed the rest of the system.
The air powered bleeder work much better than a Mityvac.

Looks nice!

One other tip for others, if you are having a hard time getting the pistons out, and using air does not do it, you can attach a grease fitting, and use a grease gun.
The grease gun puts out far more pressure than most compressors.
I have never had a piston I could not get out using a grease gun. I have using air.

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Dan Kyle said:

if you bleed the master cylinder first, it will be a lot easier to bleed the rest of the system.
The air powered bleeder work much better than a Mityvac.

Looks nice!

One other tip for others, if you are having a hard time getting the pistons out, and using air does not do it, you can attach a grease fitting, and use a grease gun.
The grease gun puts out far more pressure than most compressors.
I have never had a piston I could not get out using a grease gun. I have using air.

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What's your technique for bleeding the MC?

But try the air first, it's less messy.

You'll find a bunch of threads here about bleeding the Lockheed M/C, as everybody seems to have issues with it. Pushing fluid from the bottom up worked better for me than just pumping the lever. Some say to remove the whole system from the bike and bleed it on the bench with the caliper higher than the M/C, so the air bubbles can rise. The place where bubbles seem to get stuck is at the M/C where the brake switch is. The best piece of advice I can offer is to put the bike on the side stand and turn the forks to the left lock. That seems to put it at an angle that lets those last bubbles rise to the reservoir.

maylar said:

The best piece of advice I can offer is to put the bike on the side stand and turn the forks to the left lock. That seems to put it at an angle that lets those last bubbles rise to the reservoir.

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And then leave it overnight with a STOUT rubber band around the lever / handlebar.

Just a short history of what I remember about the introduction of DOT 5 brake fluid: The military got tired of having two types of fluid. Dot 3 for most things and Dot 4 for all the Girling brake systems that had natural rubber seals which were eroded by Dot 3 fluid. Dot 5 could go in any system at the time and solved a lot of problems since now they only had to stock one fluid. This was a long time ago and I was not in the military but it is what I remember hearing. On top of that the Dot 5 had that higher temperature rating, did not absorb water and did not ruin paint jobs. Some things have changed since then like temperature ratings and the introduction of 5.1 fluid. If I may just include a short rant about the numbering system, I wish they had called the 5.1 something like 4.5 it would be less confusing since 5 is silicone base and the others are glycol base but I probably should have put that in the pub.

swooshdave said:

What's your technique for bleeding the MC?

But try the air first, it's less messy.

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As you hold the lever in, you will need to loosen the banjo, or line that goes into the Mastercylinder.
You will need to do this until it is mostly or all fluid coming out.
Once that done it will bleed at the caliper much easier.
Be aware that Brake fluid will come out so have rags or something to soak it up.
If you are using Dot 3 or 4 have a spray bottle of water around just in case the fluid gets on anything other than the rag.
What Brake fluid did you decide on?

PS Most of the aftermarket Brembo Mastercylinders have a bleed valve on them, makes it easy.

Dan Kyle said:

As you hold the lever in, you will need to loosen the banjo, or line that goes into the Mastercylinder.
You will need to do this until it is mostly or all fluid coming out.
Once that done it will bleed at the caliper much easier.
Be aware that Brake fluid will come out so have rags or something to soak it up.
If you are using Dot 3 or 4 have a spray bottle of water around just in case the fluid gets on anything other than the rag.
What Brake fluid did you decide on?

PS Most of the aftermarket Brembo Mastercylinders have a bleed valve on them, makes it easy.

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Ok, does this look right? I just see fluid coming out, not really any bubbles. And it's not having any effect on the lever yet. Will try some more.