Trike rear brakes?

Advertise with us
Shop deals on ebay
shop deals on amazon
Classic Goldwings

Help Support Classic Goldwings:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
J

JohnB1953

Well-known member
Joined
Dec 22, 2014
Messages
100
Reaction score
13
Location
Jamestown ND
I have a 1981 GL1100 that has a Triwing it on it. It has I think a ford rear end with drum brakes. It uses the stock Goldwing rear brake cylinder. Now that cylinder was used for a single rear disc and now has 2 rear drums. Should it not have a 10# check valve for it to work properly? When I built my VW trike with rear drums I needed to add a 10# check valve in order for it to work properly and if I switch to rear disc I also have to change to a 2 # check valve.(I have been told). Any Ideas on this? Thanks John
 
I expect the caliper volume was very close to the combined volume of the slave cylinders in the drum brakes. If it works I'd forget it.
 
I wouldn't expect the stock master that pushes one cylinder to push enough volume for 2.
A Gl1800 master is fairly easy to mod in. It has more volume since it works both the rear and one front caliper. I put one on my 83 1100 and works very good.
 
The Gl1200 master cylinder also activates the rear and one of the front brakes. I tried to use it on a trike I'm building, but the volume was border-line for the disc brakes on the rear end. I chose to use a VW master cylinder and it will lockup the rear end whenever you wish.
 
Drum brake wheel cylinders have much more movement than a disc brake caliper piston, but the pistons in a wheel cylinder are smaller diameter....but they are still larger than the piston in a stock GL rear master. I'd be leery of using a stock GL cylinder on a drum/trike conversion myself, tho I've never actually done one. Seems like there would be a lot more pedal travel to apply the drums, tho in theory, the drums might actually be able to lock, if adjusted properly. :headscratch:
 
Original post did not suggest any malfunction of current brake system. He only questions if there is a need for a check valve. It is also unclear if the trike is currently in use. As to the check valves. I have no idea what need it would serve in a system serving only the rear brakes.
 
I bought the trike as a rebuild project, and never rode it. It is a kit made in Canada and they still make trikes. I asked them a few questions and they either didn't answer or the one time they did they were very vague. I have since unbolted the original GL and replaced it with a like model .On the original I saw no check valve and it was hooked to the original GL rear cylinder so I guess it must have worked. It just seems like it has a lot of movement. I am waiting on some bushings so I can finish the front fork rebuild then I can road test it and see how they work. On my VW trike I built I have a 10# check valve in the rear and I have pressure instantly when I push the pedal and can lock them up in a heart beat. I guess I am wondering if this GL would react the same way if I install a valve Which kinda has the effect of having one pump of the brakes already in the line. Like I said I will know more once I can test drive the rig
 
Well I was doing more searching on the net and according to Speedway (Americas oldest speed shop) all drum systems need a 10# check valve to work properly. They should be located as close to master cylinder as possible. Just for a test I am going to try the trike both ways so I can report back my findings. Thank you to all that have given input. It helps a lot.
 
I am confused on the check valve. How is it intended to work? Every check valve I have ever used is essentially a 1 way valve. In a brake system, if you install a check valve, apply pressure to the system, the check valve will keep pressure on the brake cylinders preventing them from releasing.

Are you sure you mean check as opposed to a proportioning valve?
 
From what I have been able to find out it has a few purposes one is it keeps just enough pressure to prevent leaking of air into the wheel cylinders when the pressure is released and from the fluid flowing back into the master cylinder if it is lower than the wheel cylinders. I have also read that the brake springs pull the brake shoes back further than needed and there for you have to push them further to engage. It takes 75 pounds to overcome the springs so that is the reason to use only a 10 pound check valve. It just is kind of a preload on the system so you don't have to pump the brakes and it is to get rid of spongey pedal. Clear as mud now? John
 
Learned something new. I always thought of the check valve being an absolute. I never considered it would bleed back some. Makes good sense now.
 
[url=https://www.classicgoldwings.com/forum/viewtopic.php?p=173525#p173525:rbh9f1d6 said:
JohnB1953 » Tue May 17, 2016 11:05 pm[/url]":rbh9f1d6]
From what I have been able to find out it has a few purposes one is it keeps just enough pressure to prevent leaking of air into the wheel cylinders when the pressure is released and from the fluid flowing back into the master cylinder if it is lower than the wheel cylinders. I have also read that the brake springs pull the brake shoes back further than needed and there for you have to push them further to engage. It takes 75 pounds to overcome the springs so that is the reason to use only a 10 pound check valve. It just is kind of a preload on the system so you don't have to pump the brakes and it is to get rid of spongey pedal. Clear as mud now? John
Click to expand...
:good:
 
Ok I have had time to work on the trike a little more this week. I got it together and rode it around, It takes a lot of effort but you can lock up the rear brakes. I am going to try to adjust them a little tighter and maybe mess with the master cylinder rod a little and see if that helps. I am going to figure out what I need for the check valve as that won't hurt anything and may just improve the brakes a little. I am not sure about the front brakes to me they could stop a little better also. The front forks did leak and I wonder if that has had a bad affect on the pads. May have to look into changing them also. But that's where I am at as of today.
 
the check valves are called residual valves and are only used on drum brakes. They are normally part of the master cylinder and range from 2psi to about 12 psi. The actual purpose for these valves is to keep air from creeping back into the wheel cylinders. There not used on disk brakes that I know of.
 

Latest posts

Top