'84 rear brake hi spot bleeder ?

[6m459]

In reading up on rear brake bleeding, I found this excellent tech library article:

 

http://www.venturerider.org/forum/showthread.php?t=490

 

I have course have no such modification on my '84 bikes but I was wondering if there is a fittng that could be undone to get the bulk of the air out of the high spot on the rear system line to the front line?

 

Thanks,

 

Brian H.

[muffinman]

I was wondering if there is a fittng that could be undone to get the bulk of the air out of the high spot on the rear system line to the front line?

 

Thanks,

 

Brian H.

There is a fitting on the tripple tree but I would suggest not opening it to try and get the air out (done that did not help).I have had no problems bleeding the brakes by the manual.

Jeff

[KarlS]

My 2 cents worth. When I got my 83VR had to completely re-do all brakes. Kept trying to bleed left front first (farthest from master rule) and got nowhere. Ever since then I bleed rear first and then front bleeds real fast. Maybe that's whats supposed to be done anyway just know it works on mine.

[Snaggletooth]

Ok, here is one I'm good at. Done it so many times I have it down to a science.

 

Make sure the rear master is full. The 1st place to bleed is the fitting called the metering valve behind the neck of the steering. The tech article calls it a proportioning valve but it's not. That is on the master cylinder itself. There is a union (bango) bolt on the rear of the metering valve that faces to the rear of the bike for the front left caliper line. On the right side of that valve is a steel line that comes from the rear master. That is the easy one to get to.

 

Rap a rag around it as much as you can to catch the brake fliud coming out and pump up the brakes. Crack the steel line fitting and tighten again as the pedal drops. Repeat as needed until it stops spitting. Check the rear master and refill.

 

Then go to the left front caliper and repeat the bleed process again as needed. Check master. Then move to the left front anti dive and repeat the process again. Check the master again.

 

Now move to the rear brake. Pump the pedal and repeat the bleed process again. When you have finished all four points in this order the feel of the pedal should be firm. Now.....check that master one more time and then bleed the rear again to remove some fluid from the system.

 

You want the master filled, but not full. It the master is topped off completely you might have problems with the rear brake dragging if the fluid heats up and expands. You need to leave a little room in there for that.

 

The reason for this patten is the air in the lines moves to the highest point in the system, the metering valve. If you don't get the air out of the high point you will never get the brakes firm. Some guys that have problems bleeding let the bike sit over night and let the air bubbles rise. Then bleed in the morning with no problems.

 

Don't forget to check the freeplay in the brake pedal when you are done. You want a lttle slack on that so the plunger in the master cylinder is not compressed until the pedal is press a bit.

 

The stainless steel lines from Rick at Buckeye have a bleeder line made into them at the metering valve connection. Nice feature.

 

Good luck

[6m459]

The 1st place to bleed is the fitting called the metering valve behind the neck of the steering. The tech article calls it a proportioning valve but it's not. That is on the master cylinder itself. There is a union (bango) bolt on the rear of the metering valve that faces to the rear of the bike for the front left caliper line. On the right side of that valve is a steel line that comes from the rear master. That is the easy one to get to.

 

 

I was looking at this last night and its not all that easy to get to, especially to catch fluid that will drip from there when I open it up and get a wrench on it at the same time as I pump the pedal!

 

I am not all together sure that I don't have a bad rear brake master cylinder. This bike is new to me and came with bad brakes. Could be just air or could be a bad m/c.

 

How best to test the m/c without getting brake fluid all over the place?

 

The bike looks to be in pretty good and unmolested state mechanically. Its odo shows low mileage but in kM's it could easily have been around once already, so its either an unbelievable 20,000 kM's or 120 or 220 I really don't know (P.O. said its 20k). My gut says its probably 120 which puts the bike in the same ballpark with my other xvz12, currently at 52,000 miles (US import). What is the general life expectancy of a rear m/c on these bikes? I have had my other bike since 20,000 miles and never had a problem with rear brakes and I don't read a lot of VR.org tech forum posts on the subject.

 

My gut says 'there is air in the lines' but my old back says 'don't contort me all up to get at that high up fitting when the problem will be the m/c'.

 

Then my brain pipes up and says 'while you are at it, why not modify that rigid line to put in a high spot bleed valve to make this easier'. (BTW, can I buy rigid line with the right fittings in automotive supply stores? What do I ask for?) Trouble is though, my brain talks a good game, but my back is less and less interested in helping out these days.

 

Who do I listen to ?

 

Thanks,

 

Brian H.

[Venturous Randy]

There is a fitting on the tripple tree but I would suggest not opening it to try and get the air out (done that did not help).I have had no problems bleeding the brakes by the manual.

 

 

Jeff

 

I agree with what jeff said. I do not have speed bleeders, so I open the bleed valve and pump a lot of fluid thru using my finger as a check valve before I actually start to bleed. I also did the fitting at the tree and it did not seem to help any.

RandyA