lario front master cylinder

[Chuck in Indiana]

rebuild kit available? Fading memory says not, but maybe it's wrong? 

[Antietam Classic Cycle]

Did a search and came up with this:

https://www.retzmoto.com/partiecycle/pneumatiques/169082_brembo-m-c_kit-reparation-maitre-cylindre-av-ps12-moto-guzzi-v35-v50-v65-t5-10409020.html

[Cdn850T5NT]

https://www.motogiovane.com/mobile_products.php?cPath=67&page=6

Moto Giovane has the kit, without the piston. You'd 'hafta turn, on the lathe, a cone for each side of the piston, lubed with EPDM compatible grease, to install these on your old piston in a damage-free manner, assuming the piston is not pitted. Same with the m/c bore, re lack of pits.

Lotsa places list this NLA item... but they all say "out of stock". I think Moto Giovane actually has product.

There's an error in my pic. Cost is 40 Euro, not 19...

[Chuck in Indiana]

Thanks guys..

[guzziart]

Hi Chuck,

I think you may be running the Brembo trapezoid shaped reservoir model MC, like what I have on my '87 Lemans.  Brembo no longer supports the product.... I've been in touch with them with no success.  When I bought pump & reservoir rebuild kits in 2010 from Moto International, I requested two of each, their response was that they only have one of each and they’re probably the last ones in existence

I reached out to Apple Hydraulics, they rebuild/re-sleeve MC’s, a few weeks ago but they never responded to my email inquiry.  I should probably call them.  I also reached out to Cycle Garden, Moe said he’d look into it but hasn’t gotten back to me yet either.  I called Mark Etheridge and basically he’s got nothing for these.

Since the pump portion of my MC is not leaking, the reservoir gasket seeps, I was contemplating a mod to the assembly that would allow a remote reservoir to be connected.  I would prefer to get my hands on a fubar assembly to mock-up versus tearing off my MC and butchering to a point of total uselessness.

Art





NLA
MG# 2866 0200, MC Asm
MG# 2866 1100, Pump Cover Kit & Diaphragm
MG# 2865 9300,  Gasket Kit for Brake Pump

Update:  *****The piston dimensions in my post are approximates.  I'm not a Master Tool & Diemaker nor machinist but have a HF digital caliper ****

[huub]

for the pump section , order a universal one from aliexpress ( 4 euro including shipping) and cut it to size on the lathe.
took me 20 minutes for my lario.
has been working fine for years

[Cdn850T5NT]

Huub, can you explain a bit more, regarding fitting a universal master cylinder section, and cutting it to size and fitting it to the rest of the Lario/T5/LeMansIV switchgear/lever section? Even photos, too, would be helpful.

Or, do I have this wrong. Did you take a nominally 12.7mm piston, remove the seals, turn it down to 12.67mm, mill the length, turn-down other parts of its diameter? Did you have it anodized afterwards?

[Cdn850T5NT]

Hi Chuck,

I think you may be running the Brembo trapezoid shaped reservoir model MC, like what I have on my '87 Lemans.  Brembo no longer supports the product.... I've been in touch with them with no success.  When I bought pump & reservoir rebuild kits in 2010 from Moto International, I requested two of each, their response was that they only have one of each and they’re probably the last ones in existence

I reached out to Apple Hydraulics, they rebuild/re-sleeve MC’s, a few weeks ago but they never responded to my email inquiry.  I should probably call them.  I also reached out to Cycle Garden, Moe said he’d look into it but hasn’t gotten back to me yet either.  I called Mark Etheridge and basically he’s got nothing for these.

Since the pump portion of my MC is not leaking, the reservoir gasket seeps, I was contemplating a mod to the assembly that would allow a remote reservoir to be connected.  I would prefer to get my hands on a fubar assembly to mock-up versus tearing off my MC and butchering to a point of total uselessness.

Art





NLA
MG# 2866 0200, MC Asm
MG# 2866 1100, Pump Cover Kit & Diaphragm
MG# 2865 9300,  Gasket Kit for Brake Pump

Guzziart, excellent work on this! Can you refresh my memory, here. What does that intermediate, smaller (nominally) trapezoidal piece do? Does it fit inside the reservoir?

Re a leaking top-gasket: what about cutting a piece of 6061T6 to emulate the plastic top cover, with exact drilled and countersunk bolt holes/pattern, but say 3mm/ 1/8" larger perimeter. Then drill and tap centre of said piece say 1/8" NPT, and fitting a vent. Then taking a suitable durometer sheet of EPDM, and punching a hole in it, corresponding to the vent location, and bonding it to the underside of the 6061 top cover. The edges of the reservoir act as blunt knife-edges to seal against the EPDM. The adhesive used must be suitable for both brake fluid and EPDM.

You lose the nominally air-tight nature of the orig top gasket... but change brake fluid more often.

Does this work?

Oh, btw, they say that sleeving a bore to brass is the best. Not to aluminum or stainless steel, in cases like this, if the bore is pitted. Whitepost Restorations may be able to do this??

https://whitepost.com/brake-sleeving-rebuilding-services/

[huub]

i used a  rebuild kit from aliexpress, just needed the part sticking out of the cylinder shortened.
https://nl.aliexpress.com/item/1005001924534581.html?spm=a2g0o.productlist.0.0.7c0d1c89WGvRSO&algo_pvid=3f3b1117-0b6a-4d16-8f48-a3a83eb91d9e&algo_exp_id=3f3b1117-0b6a-4d16-8f48-a3a83eb91d9e-0&pdp_ext_f=%7B%22sku_id%22%3A%2212000018126375579%22%7D&pdp_npi=2%40dis%21EUR%21%211.24%21%21%212.9%21%21%402100bddd16576538464446160e9462%2112000018126375579%21sea
it  was a couple of years ago , i'm not sure it exactly this one , but you get the point.

the epdm you use on roofs is brake fluid resistant, you can use that for the gasket of the reservoir

[Cdn850T5NT]

👍. I'm not sure if the 12.7mm versus 12.67mm matters. It might be that the bore is 12.7. And the piston is 12.67?

[guzziart]

Guzziart, excellent work on this! Can you refresh my memory, here. What does that intermediate, smaller (nominally) trapezoidal piece do? Does it fit inside the reservoir?

Re a leaking top-gasket: what about cutting a piece of 6061T6 to emulate the plastic top cover, with exact drilled and countersunk bolt holes/pattern, but say 3mm/ 1/8" larger perimeter. Then drill and tap centre of said piece say 1/8" NPT, and fitting a vent. Then taking a suitable durometer sheet of EPDM, and punching a hole in it, corresponding to the vent location, and bonding it to the underside of the 6061 top cover. The edges of the reservoir act as blunt knife-edges to seal against the EPDM. The adhesive used must be suitable for both brake fluid and EPDM.

You lose the nominally air-tight nature of the orig top gasket... but change brake fluid more often.

Does this work?

Oh, btw, they say that sleeving a bore to brass is the best. Not to aluminum or stainless steel, in cases like this, if the bore is pitted. Whitepost Restorations may be able to do this??

https://whitepost.com/brake-sleeving-rebuilding-services/

The trap shaped piece resides between the cover and diaphragm.

The mod you describe makes me think that I could probably remove the entire (trapezoid) reservoir and replace it with a solid (metal) gasketed cover right to the pump body, fit it with a nipple in the center that would receive fluid from a remote reservoir.  Or is that what you're eluding to??!!  Anyway, I'd like to get my hands on a used/fubar one to aid in research & development.  I really hate to get involved with replacing the switch gear, throttle tube, etc. because of a leaky rez.

When I rebuilt the MC in 2010, the pump bore was in nice shape considering the bike had been sitting since the mid '90's with the same fluid

Thanks for the Whitepost recommendation.  As it is now Chuck and I, I also know of a 3rd fellow tha has a leaky trap MC.....there's gotta be more out there that weep, seep or leak.

Art

*****The piston dimensions in my post are approximates.  I'm not a Master Tool & Diemaker nor machinist but have a HF digital caliper ****

[Chuck in Indiana]

Anyway, I'd like to get my hands on a used/fubar one to aid in research & development.

Milich has one on ebay right now, but he wants $80 for it. I'm sure it would meet your specifications. 

[guzziart]

Milich has one on ebay right now, but he wants $80 for it. I'm sure it would meet your specifications. 

Yeah, I placed a couple bids on it that were subsequently rejected

Update: A few weeks after this post I reached out to Ed and we agreed on a price but he was then unable to find the pump.

[Cdn850T5NT]

The trap shaped piece resides between the cover and diaphragm.

The mod you describe makes me think that I could probably remove the entire (trapezoid) reservoir and replace it with a solid (metal) gasketed cover right to the pump body, fit it with a nipple in the center that would receive fluid from a remote reservoir.  Or is that what you're eluding to??!!  Anyway, I'd like to get my hands on a used/fubar one to aid in research & development.  I really hate to get involved with replacing the switch gear, throttle tube, etc. because of a leaky rez.

When I rebuilt the MC in 2010, the pump bore was in nice shape considering the bike had been sitting since the mid '90's with the same fluid

Thanks for the Whitepost recommendation.  As it is now Chuck and I, I also know of a 3rd fellow tha has a leaky trap MC.....there's gotta be more out there that weep, seep or leak.

Art

*****The piston dimensions in my post are approximates.  I'm not a Master Tool & Diemaker nor machinist but have a HF digital caliper ****

Sorry for the delay, Art.

What I was suggesting was that if you manage to bond the EPDM to the underside of a new 6061T6 cover, and if the bond is sound and brake-fluid-tight, and if the EPDM were sufficiently low durometer hardness, then simply bolting down the new cover may be enough to seal against the original reservoir. It might be possible to enhance that bond, just a bit, with a suitable and chemically compatible tack-agent? That would not be as practical, but...

While we're on this subject (i.e. not wanting to replace this whole assembly due to lever perch's, throttle, switchgear, please note that Chuck in Indiana cracked the case re how to service the switchgear (and importantly, how to reassemble the switches)... and he and I both have the pictures for same. They were lost from his Lario rebuild how-to due to a hosting issue I believe .. And ii) I'd like to talk about the throttle cable termination on this rig, following...

The bailing wire over-centre retaining wire was light-gauge wire on mine, would always increase the throttle play, and get to the point of nearly falling off, disconnecting the throttle cables from the throttle! Well, my late Dad, who could fashion a set of shoes for a housefly set about revising the arrangement and remaining to look stock. He fashioned a fairly narrow piece of brass bar stock, bending it in a vice, to confirm with the plastic cable termination piece. It has two holes at the bottom of its pocket (for the twin throttle cables), he soldered light gauge brass shimstock to the sides (to close-in the pocket) and painted it satin black. Throttle assembly is drilled and tapped (small screw) at its front, and the former screw which tightened the throttle action is used to hold its back portion up in place. Said bolt is centrally drilled and threaded... and brass screw thread-portion acts to control throttle stiffness. A  tri-light lamp knurled-surface knob is jam-nutted onto the brass thread... and now controls throttle stiffness.

See picture attached. Zoom-in in that area of the pix...



white medium square emojis

[guzziart]

Hi Cdn850,

When I discussed my seepy reservoir with Mark Etheridge (MG Classics), he said don't worry about it, it will stop.  I figured sure it will stop...when I'm completely out of fluid!  Well, the reservoir has stopped seeping fluid and is still fluid in it.  For the time being I don't plan on doing anything further with it but i know it will probably be an issue at the next fluid change. 

I'm now thinking of a different tack.  The reservoir bottom fluid seal to the pump body is accomplished with an o-ring.  I think I can remove the whole reservoir off of the top of the pump and replace it with a custom made adapter/nipple that will hold an o-ring.  The adapter could be connected to a remote reservoir.  The adapter would be held in place with a faux trapezoidal shaped cap.  I'd require help from my machinist pal to fab the adapter & trap cap but this mod could possibly eliminate future problems and I'd lose the aesthetic trapezoid appearance for a conventional cylindrical shaped reservoir.  We'll see I guess.

As for your throttle stay modification goes...it looks great, your dad did a nice job!  My LMIV came to me as shown in the photo below.  The adjusting barrels allow for carb sync since my bellcrank 40's have no provision at the carbs for cable sync/balance.  Also, the bike came with pod air filters so to further maintain carb sync I installed Delrin manifolds.  The rubber oem manifolds could not sufficiently support the carbs & pods.  And the carbs have been re-jetted per Ed Millich's "recipe" which made a huge difference in overall performance....fwiw .





Speaking of switch gear, I tore into those back in 2010..cleaning & lubing but also installed relays to eliminate high current through them and have had no problems since.  Although I was able to get my hands on NOS switches, I haven't needed them yet....they'll go to the next caretaker (lol).

[Cdn850T5NT]

Hi Cdn850,

When I discussed my seepy reservoir with Mark Etheridge (MG Classics), he said don't worry about it, it will stop.  I figured sure it will stop...when I'm completely out of fluid!  Well, the reservoir has stopped seeping fluid and is still fluid in it.  For the time being I don't plan on doing anything further with it but i know it will probably be an issue at the next fluid change. 

I'm now thinking of a different tack.  The reservoir bottom fluid seal to the pump body is accomplished with an o-ring.  I think I can remove the whole reservoir off of the top of the pump and replace it with a custom made adapter/nipple that will hold an o-ring.  The adapter could be connected to a remote reservoir.  The adapter would be held in place with a faux trapezoidal shaped cap.  I'd require help from my machinist pal to fab the adapter & trap cap but this mod could possibly eliminate future problems and I'd lose the aesthetic trapezoid appearance for a conventional cylindrical shaped reservoir.  We'll see I guess.

As for your throttle stay modification goes...it looks great, your dad did a nice job!  My LMIV came to me as shown in the photo below.  The adjusting barrels allow for carb sync since my bellcrank 40's have no provision at the carbs for cable sync/balance.  Also, the bike came with pod air filters so to further maintain carb sync I installed Delrin manifolds.  The rubber oem manifolds could not sufficiently support the carbs & pods.  And the carbs have been re-jetted per Ed Millich's "recipe" which made a huge difference in overall performance....fwiw .





Speaking of switch gear, I tore into those back in 2010..cleaning & lubing but also installed relays to eliminate high current through them and have had no problems since.  Although I was able to get my hands on NOS switches, I haven't needed them yet....they'll go to the next caretaker (lol).

Looks great, Guzziart. And kudos to you re figuring out the switchgear and doing the relay work to save the switches going forward. I need to do that.

Re the bailing wire clip still evident on your bike, well, I must have been too vigorously closing the throttle, because each time, it'd stretch the spring. It struck me that the spring was extremely light duty, thin gauge. I wonder if subsequent to my Nov '84 built T5 they went huskier on it, especially since I have not heard many complaints with the issue on this forum?

Cheers!

[Cdn850T5NT]

@guzziart, I'm confused re a remote reservoir, in that where could you locate it such that the hose continuously goes uphill to the reservoir, i.e. so as to not make a spot for air to accumulate? Is it that said remote reservoir is temporarily "un-clipped" and held continuously upright, above, during any bleeding operation?

[Chuck in Indiana]

I ordered Huub's kit from Ali Baba at 99 cents  plus 3 dollars and some shipping. Supposed to get here in September. That would be fine. Mine has been occasionally needing bled as the lever creeps toward the grip. It never has been really firm, but works ok. Maybe this kit will fix it. If not.. I'll be out almost 5 bucks. (Guzzi content) 

[Cdn850T5NT]

Folks can try to pressure-bleed in reverse if the air is being stubborn if:

i) the syringe they use has limited stiction... and this is tested, first, in brake fluid.. AWAY from the bike; and
ii) paintwork is liberally covered-up with sheets, rags first.

Suffice it to say, first, withdraw some fluid, and loosely refit the cover prior to starting 🙂.

[guzziart]

@guzziart, I'm confused re a remote reservoir, in that where could you locate it such that the hose continuously goes uphill to the reservoir, i.e. so as to not make a spot for air to accumulate? Is it that said remote reservoir is temporarily "un-clipped" and held continuously upright, above, during any bleeding operation?

Hi Cdn,

When I refer to "remote" reservoir,  I'm talking about installing a reservoir that is similar to what comes on sports bikes, etc.  The reservoir is mounted an inch or two above the pump, on a bracket, and has a hose from the bottom of the reservoir to the supply inlet of the pump.  This is a pic of the remote (factory) res on my '03 Lemans.





I think I can completely separate the trap res from the LMIV brake pump and replace it with a remote set-up.  And, do it without making irreversible changes to the pump body so if someone starts re-producing reservoirs, caps & diaphragms, it can be returned to oem appearance.  However, since it has stopped weeping, I have slightly backed off of doing anything to it right now and been riding the bike.

Art

[Cdn850T5NT]

  thx... I see it is continuously uphill, and very close-coupled.

I like the notion of reversable changes 🙂.

Cheers!

[guzziart]

Good luck Chuck! 
I'm interested in hearing of your experiences with the Lario front brake master cylinder pump repair.
Art

[Chuck in Indiana]

Good luck Chuck! 
I'm interested in hearing of your experiences with the Lario front brake master cylinder pump repair.
Art

Hiya Art.. be patient.  I just received an email saying expected delivery is September 13. That is still prime riding weather, though, so I most likely won't open that can of worms until Winter. If it works, I'll do a tutorial.

[Cdn850T5NT]

Yeah, I'm interested, too, Chuck. I'm also wondering about piston diameters... I wonder if for a 12.7mm bore, the piston (though stated as a nominal 12.7mm) is something like 12.67mm... Also wondering about the type of (small) snap ring tool you use.

Good luck!

[Groover]

Following - may need this info some day. Cnd850TNT, thanks for the Heads-up on this thread. ChuckinIndiana, thanks for the thread.