new "offshore" front master cylinder

[Jonesz]

Ordered a master cylinder from an ebay seller that packages a Gl1000 front master cylinder and a clutch set-up. Haven't mounted the clutch perch etc. as yet but have had no success with the front brake master cylinder. My friend (a long time mechanic) and I have tried every way we could think of to bleed what feels like "air" in my brake system. The brake lever has a spongy feel and in a side by side with my 1100 feels like the brake system would be as Ralph Nader said "unsafe at any speed". Wondering if anyone else on this site has experienced the same brake feel after installing what seemed like a "bargain" replacement. I have just now written to the vendor asking for a replacement or repair kit for this system. BTW my 40 year old HONDA master cylinder works as it should after all these years, it just looked very worn and tired.

[RB]

WHAT SELLER?? one to stay away from???

[Jonesz]

WHAT SELLER?? one to stay away from???

Not sure until I hear back from the seller. It may be a unforeseen manufacturing problem or? I wouldn't say that they are to stay away from until I hear/don't hear back from them. I have had other parts failures in the past and the one we are discussing here was a cheapo replacement. Just wondered if other folks on this site who have bought the same controls were happy. I did see a recent thread where similar levers/master cylinder were bought with no problem. I was particularly interested in whether the spongy feel was due to the "nature of the beast".

[Explorer]

A good few years ago I bought what was billed as a universal master cylinder from China. As soon as it was bled the viewing window melted. True story. Ended up with a CB900 NOS, still on there!

[jdvorchak]

Here is the method I use on new master cylinders. I install it hook up everything but the brake line. But since you've been trying to bleed the system I advise this. First and foremost cover all of the painted surfaces with plastic and/or rags because fluid will be released as squirt. Remove the brake line from the master cylinder. Top up the master with fluid. Hold your thumb or finger over the brake line fitting where the brake line would attach. Slowly pump the brake lever, while holding your thumb over the outlet. At first you may feel vacuum then in one or two more pumps the fluid will push past your thumb. It may take quite a few pumps but it will eventually bleed the air out. Try to hold it and pump one or two more times. While still holding your thumb over the outlet let the brake lever return to it's relaxed position. Hook up the brake line and tighten. That is the only way to bleed a MC that I know that works every time. Top up the fluid level and you should be good to go. Good luck.

[JSBail]

I've got one of those ebay M/C's on my wife's cb350 and it too had a spongy feel to it at first but the spongyness seemed to go away after it sat overnight after I bled everything. It's been on the bike for a couple of years now and haven't had an issue with so far.

[Jonesz]

Thanx all for the replies so far. Will try bleed the MC like your advise JDvorchak. I did get a reply back from the vendor. He would like a picture?? he also asked if the MC was hooked up to one or multiple calipers, although it was advertised to fit a 78 gl1000. Says he will try figure something out.
I was also wondering if the MC lacked capacity. You can visibly see the brake lines swell when the lever is pulled so was also wondering if braided brake lines would help the situation?
Just a couple of thoughts. There is a similar MC on my 83 gl1100 (installed by the previous owner))and it works fine, however in that case there is only one caliper being activated by the front lever due to the linked system on that bike.

[wingandaprayer]

I would have to say that if you can see the brake hoses visibly swell (as opposed to just moving) then you have no chance of getting a firm lever, in fact there is a risk of complete brake failure - braided lines would be good

[Track T 2411]

+1 on pre - bleeding the master cylinder, as well as investing in stainless steel lines. Night and day difference. My 2 cents...

[Jonesz]

Well guys we have tried almost everything with no joy and am now waiting for a second reply from the vendor. Last on our list is to find a suitable bolt to block the master cylinder and see if we can get a firm feel to the brake lever. Also going to check into SS brake lines to replace those 40 yr old ones. I misspoke when I said the old hoses swell and like Wingandaprayer mentioned they are basically moving not visibly swelling.

[Track T 2411]

Have you disassembled the new master cylinder to make sure the innards are in the right order/ orientation? IIRC, someone here had a similar problem and the rubber was installed backwards. Just a thought...

[Jonesz]

Hey Track T, that will go on the list. My mechanic buddy mentioned that he has run across improper assembly in the past. Guessing nothing can be overlooked at this point so we will give that a try as a last resort. Wish I had ordered the MC with repair kit included as some on Ebay are. That should have been an indicator of quality right? As I said while my 40 year old Honda Master Cylinder is now unsightly due to the reservoir plastic deteriorating etc. it still works. I do like the lower profile of the new unit tho.and really hope to get it functioning properly.

[jdvorchak]

Since you're basically just waiting now. Try this as a last resort. Put the bike on the sidestand. Turn the handle bars all the way to the left. Tie the brake lever down almost all the way to the grip with a bungee or wire or what ever. Leave it alone over night. Also helps if the master cylinder is positioned on the handle bar so the reservoir is the highest point with the brake line connection at the lowest part. Any trapped air bubbles will work their way to the top and with the lever tied back the spooge hole(s) is uncovered letting the air out.

[Jonesz]

Kind of wondering.Got another reply back from the seller last night and he now says that the the master cylinder with the 14mm bore is not sufficient to properly work a two caliper system even though it was advertised to fit a 78 gl1000. He says that I require a master cylinder with a 16mm bore? I told him enough was enough and to either refund my $ or ship one with a 16mm bore as a replacement. We will see.
BTW Track T and others that have gone to stainless braided lines might be able to tell me if the new lines would enhance the brakes to a point where the 14mm master cylinder is adequate?
JDVorchak can't put it on the side stand right now as the tank and rear wheel are out of the bike. So on the lift it stays for now. Might try just cranking the handle bar over with the lever tied down anyway and the master cylinder in the best location to elevate the reservoir. If that doesn't work will try your trick once it comes off the lift. Thanx for that.
Have also contacted Apex and they have a braided four line kit for my bike. 3 for the front and one rear line. Might go that route anyway just to get rid of the 40 year old ones. They sent a reply and price (including freight) right away and seem helpful. Not cheap but they ship from Canada so don't have to go through customs etc. and payable in Canadian bucks so I know how much before I order.

[Rat]

I can recommend Apex from personal experience ....

Gord