RGM Front M/C Sleeve Kit

I recently purchased and installed the RGM M/C Sleeve Kit for my '75 E-Start. It is the latest version of the design using the threaded sleeve, the thick nitrile seal for the bottom of the bore, and the adjustable pusher. The sleeve comes with the primary & secondary feed holes pre-drilled and the bore is already honed. The kit was shipped to me with the incorrect installation instruction but I was able to muddle through it reasonably well. But after installation and bleeding of the system, it developed a leak within 24 hrs. The way I see it there are two possible sources for the leak; fluid bypassing the secondary seal (an "o" ring), or fluid leaking past the threads holding the sleeve into the bore.


I had sent a message to RGM asking numerous questions about the installation prior to attempting it. Yesterday I received the correct installation instructions from them in the mail. It apears that my installation followed the instructions to the tee, with the exception that I didn't wipe some silicone sealer into the threads that hold the sleeve into the bore. The sleeve came with teflon tape wrapped around the threads...I figured that would be adequate. Guess I was wrong.

So I plan on disassembling the unit, removing the sleeve and trying to seal up those threads with silly seal. Naturally I will be giving a close inspection to the secondary seal o ring too. I was considering installing a quad seal (x-ring) in the o-ring's place. Any other suggestions/lessons learned would be appreciated.

Thanks for the help,

Is this kit for the front MC?

If so, I'm interested in learning more about it as I, too, have a MKIII with that "unique" front master cylinder. I couldn't find any info about the MC kit on the RGM website; so, could you post some information / pictures?

Teflon tape and silicone sealer are generally not recommended for use on hydraulic brake system components for fear it could clog up one of the small orifices. So, be sparing with this stuff.

Regards,

Jason

Jason Curtiss said:

If so, I'm interested in learning more about it as I, too, have a MKIII with that "unique" front master cylinder. I couldn't find any info about the MC kit on the RGM website; so, could you post some information / pictures?

Click to expand...

I sent my 850 MkIII front M/C to RGM last year to have the 13mm piston kit fitted (as that was the easiest option), and I have had no problems with it.
It does improve the braking feel and performance, which is somewhat limited by the original caliper that I still use.

Picture from the RGM website:

"713D 050136 MASTER CYLINDER RE LINE KIT WITH INSTRUCTIONS. A SUPER IMPROVEMENT FOR THE STD NORTON FRONT MASTER CYLINDER. NOT RECOMMENDED FOR AMATEUR INSTALLATION. PLEASE SEND YOUR MASTER CYLINDER TO US IF YOU ARE IN DOUBT(SEE 713C)
G31"




http://www.rgmmotors.co.uk/home.htm

I fitted the RGM kit about a year ago and it makes a big improvement to the power and progressiveness of the front brake. I still retain the standard caliper for originality but overhauled that, too,using stainless pistons (which I polished until they looked like chrome).
I also had a lot of difficulty with the instructions and sent RGM a drawing of the dimensions of my master cylinder relative to their kit. Holes and dimensions seemed wrong to me and did not line up where they should. Also the length of tapped hole into the original bore was insufficient to ensure that the reduction sleeve, when screwed in, would bottom out properly against the fibre seal in the bottom of the bore.
All got resolved eventually but it was not straightforward, aggravated by the apparent variances in production tolerances for the original Norton-Lockheed cylinder.
The kit shown in L.A.B's picture is the same as I fitted, whereas I understand the latest RGM kits use a different seal in the bore bottom and use an adjustable pusher (which I fitted to mine retospectively to get better lever travel with the Lockheed racing lever).
The RGM kit is a worthwhile mod.

My kit is like the one pictured above, but it's slightly updated. It came with the adjustable pusher and a nitrile sealing washer (that gets fitted into the bottom of the M/C bore), replacing the red fiber sealing washer. The nitrile washer is about 1/8" - 3/16" thick. With that washer fitted, the grooves in the sleeve did not line up with the existing supply holes in the reservoir. I had to remove aprox. .110" off the blind end of the sleeve so that it could be screwed in deep enough for the grooves to line up with the reservoir supply holes. When I finally got the sleeve fitted, I was surprised to find that the supply holes in the sleeve lined up with the supply holes in the reservoir - I lucked out I guess. The adjustable pusher made short work of getting the piston adjusted correctly. The M/C bled easily and holds pressure just fine, so my leak is not from the primary seal bypassing or fluid leaking past the nitrile washer. My leak is either past the secondary piston seal (o-ring) or past the threads on the sleeve.

When I received the kit, the threads on the sleeve were wrapped with teflon tape. The new instructions I received also showed the threads wrapped in Teflon tape, and the instructions tell you to wipe some silly seal into the threads of the M/C bore, so I guess they are telling the installer to use both.

The piston assembly supplied in the RGM kit is from a Grimeca 13mm master cylinder. Brembo calipers use the same design, i.e, a cup seal for primary and an o-ring for secondary. I prefer the original Lockheed design that uses two cup seals - just seems like the secondary cup would seal better than an o-ring and probably would last longer. I was considering replacing the standard o-ring with a quad ring having an "x" cross section, which would double the sealing surfaces. Anybody have any experience?

Thanks for your input - it's been helpful!

scim77 stated...

I still retain the standard caliper for originality but overhauled that, too,using stainless pistons (which I polished until they looked like chrome).

I also fitted some stainless caliper pistons in my caliper. Is there an improvement in performance to be gained by polishing them as you have?

I considered that by polishing the pistons they would be less likely to develop witness marks in the caliper seals. This in turn would enable the pistons to creep out more easily as the pads wear down but without risk of encountering new tiny marks in the pistons, which might nip the seals or cause a leak. They should be less prone to seizure, albeit within the constraints of the rather crude caliper design which has no weather seal to exclude moisture.
I am generally of the opinion that the best surface finish on components is usually an advantage for smooth operation and long life.
My brakes certainly feel confidence inspiring now, a statement which would have been inconceivable in their original form.
p.s. stainless steel is very hard and laborious to polish, too !

hi - i have fitter the RGM kit and tried to follow the instructions without much success and have tried to bleed the system as follows:
1. hand held with supplied bleed nipple - appeared to bleed all air but upon assembling to handlebar the air got back in
2. tried normal fitment and bleeding from the nipple end at the caliber - no luck at all - even with fluid pumpedback through both holes in reservoir (the adjustable lever stop appears to work well)
3. tried bleeding from the top and turning handlebars fully to the left to allow air to rise and bubble out
4. tied the lever back and left overnight and over night etc
5. tried a syringe to push fluid up from the caliber end but just made a mess
6. two weeks later i don't appear to be getting anywhere close to taking my 1975 mk3 out on the road

has anyone got another suggestion?

perhaps i should book it in to a norton commando specialist but then i would be defeated

thanks for any comments

I brought the RGM kit a few years ago but never put it in, after looking at my old braking system I decided to up grade the whole front brakes to Grimica system (after my front brakes tried to kill me), 12" floating disc, Grimica M/C and S/S brake line, this set up looks great, works well without any effort, I am glad I went down this road as its one of the best improvements I have done (of many improvements over the last 6 years) and after 6 years on the bike I have had no problems with the Grimica set up, yes there are better set ups in todays markets but this set up works good for me.
My riding time and safety is more important than keeping my 40 year old brakes that have always had problems with stopping, they worked well when new but fade away as they got older and the roads are getting more dangours (more cars on the road, mobil phones, poeple not paying attention etc etc).

Ashley

terencem58 said:

hi - i have fitter the RGM kit and tried to follow the instructions without much success and have tried to bleed the system as follows:

Click to expand...

"Fitting the RGM kit without much success"

Concerned that you may have something wrong in the "fitting" part. Not getting any pressure from the MC? Is it assembled properly?

Do you get any fluid out of the bleeder when you pump the brake lever?

Sometimes getting the air out can be a real pain. If you can get a better fitting for the feed of fluid from the caliper back to the MC you may have better results. This can be difficult and messy but a proper hose with clamps can make a difference. You want to see fluid feeding back to the MC when you do this.

Several years ago I bought a few items from RGM's special parts cat. Inc belt drive set up with outrigger bearing support and alloy swingarm, for a café racer I was building. I don't know if its because the parts were going overseas or not but when the parts arrived, they were either very poor quality or not finished. Even bought a set of gauge holders that were trash (one had a gouge in it that had been polished out leaving a large divot in what was supposed to be new holders. Still have them, might post a pick )
When I complained, I was told to take my business elsewhere. SO I DID. :evil:
Let the buyer beware.
jug

terencem58 said:

hi - i have fitter the RGM kit and tried to follow the instructions without much success and have tried to bleed the system as follows:
1. hand held with supplied bleed nipple - appeared to bleed all air but upon assembling to handlebar the air got back in
2. tried normal fitment and bleeding from the nipple end at the caliber - no luck at all - even with fluid pumpedback through both holes in reservoir (the adjustable lever stop appears to work well)
3. tried bleeding from the top and turning handlebars fully to the left to allow air to rise and bubble out
4. tied the lever back and left overnight and over night etc
5. tried a syringe to push fluid up from the caliber end but just made a mess
6. two weeks later i don't appear to be getting anywhere close to taking my 1975 mk3 out on the road

has anyone got another suggestion?

Click to expand...

The basic problem with the sleeve kits is that the two vent/bleed holes in the sleeve may not line up with the holes in the existing master cylinder so unless the following procedure is used during the bleeding process: "Holding the master cylinder vertically and rotating the upper end in a circle...." air can remain trapped in the master cylinder. It seems you almost succeeded at "1. hand held with supplied bleed nipple - appeared to bleed all air but upon assembling to handlebar the air got back in" but perhaps didn't continue long enough for all the air to be expelled as air shouldn't exactly "get back in" it must still have been in there. With the master cylinder held vertically (lever upwards) tapping the cylinder gently and also repeatedly operating the lever over a short distance can help the air to escape.



https://www.oldbritts.com/14_061939.html

If the hole dont line up , is it ok to drill 2 new holes ?

Michael

Egholt said:

If the hole dont line up , is it ok to drill 2 new holes ?

Click to expand...

I have always wondered why there aren't more holes in the sleeve (so at least one hole would be close to the top of the cylinder with the master cylinder fixed in its usual position)? However it would take a fairly small drill bit and I don't know what size the sleeve holes are-but the vent hole in the master cylinder isn't much bigger than 0.025" and any burring where the drill broke through would need to be carefully removed (without scoring the bore) otherwise it would damage the piston seal.

terencem58 said:

hi - i have fitter the RGM kit and tried to follow the instructions without much success and have tried to bleed the system as follows:
1. hand held with supplied bleed nipple - appeared to bleed all air but upon assembling to handlebar the air got back in
2. tried normal fitment and bleeding from the nipple end at the caliber - no luck at all - even with fluid pumpedback through both holes in reservoir (the adjustable lever stop appears to work well)
3. tried bleeding from the top and turning handlebars fully to the left to allow air to rise and bubble out
4. tied the lever back and left overnight and over night etc
5. tried a syringe to push fluid up from the caliber end but just made a mess
6. two weeks later i don't appear to be getting anywhere close to taking my 1975 mk3 out on the road

has anyone got another suggestion?

perhaps i should book it in to a norton commando specialist but then i would be defeated

thanks for any comments

Click to expand...

The way I got the air out of mine was to detach the MC from the switch gear, hold it vertical, and bleed it from the bottom whilst moving it, the MC around. One syringe full did it.

terencem58 said:

hi - i have fitter the RGM kit and tried to follow the instructions without much success and have tried to bleed the system as follows:
1. hand held with supplied bleed nipple - appeared to bleed all air but upon assembling to handlebar the air got back in
2. tried normal fitment and bleeding from the nipple end at the caliber - no luck at all - even with fluid pumpedback through both holes in reservoir (the adjustable lever stop appears to work well)
3. tried bleeding from the top and turning handlebars fully to the left to allow air to rise and bubble out
4. tied the lever back and left overnight and over night etc
5. tried a syringe to push fluid up from the caliber end but just made a mess
6. two weeks later i don't appear to be getting anywhere close to taking my 1975 mk3 out on the road

has anyone got another suggestion?

perhaps i should book it in to a norton commando specialist but then i would be defeated

thanks for any comments

Click to expand...

Terencem58,
One thing that you must do is to tap the thread depth deep enough for the insert. The end where the rubber washer sits must be compressed. If you don't have compression in this location then you will never get the M/C to move fluid to the caliper. It will just bypass around the brass insert. Its a bit of a fidget with fit and try. It happened to me on one of my rebuilt kits going in and that is how I corrected it to work. I mark the Threaded end radially with a sharpie where the hole are in the brass insert so when I tap inward I want to have these pointing up inline with the holes in the M/C fluid reservoir. This seems to aid in the bleeding. I bleed with a syringe from the caliper up to the M/C. Give that a try.
Cheers,
Thomas
CNN

thanks everyone

i will try holding the MC vertical and rotate the cylinder to get air out - will update soon

Thanks to everyone for the help offered to solve my problem. I must add that RGM were superb in helping explain the details of the sleeving instructions and have committed to update a release a new version shortly.

my experience of fitting the front master cylinder, after sleeving, is that the use of a good syringe is the only option of getting fluid into the whole system.

I found that the adjustable plunger had to be fully forward while initially filling with fluid and then adjusted back a little at a time per bleed

bleeding the system meant having the master cylinder hand held at an angle to allow for air to escape

hope this helps anyone trying the same upgrade

terencem58 said:

Thanks to everyone for the help offered to solve my problem. I must add that RGM were superb in helping explain the details of the sleeving instructions and have committed to update a release a new version shortly.

my experience of fitting the front master cylinder, after sleeving, is that the use of a good syringe is the only option of getting fluid into the whole system.

I found that the adjustable plunger had to be fully forward while initially filling with fluid and then adjusted back a little at a time per bleed

bleeding the system meant having the master cylinder hand held at an angle to allow for air to escape

hope this helps anyone trying the same upgrade

Click to expand...

Please,
Could you explain to me the best way to bleed the system?
Thank you
Piero

I've fitted three RGM sleeved M/Cyls now, one done by RGM and two done by myself.

Although it's never been a 5-minute job I've had no major issues bleeding any of them apart from having to be patient with getting all the air out. After doing a 'normal' bleed operation I keep the caliper loose and twist it so the pads are pushed back, pushing the fluid back up the line into the M/Cyl - this seems to get any trapped air out.

I was concerned about lining the holes up in the sleeve but I'm no longer sure this is actually important - it seems to just work, providing the piston is allowed to withdraw sufficiently to clear the holes.