'77 GS750 Mad Max Cafe

[gmayer]

The bike is 1077 GS750. When I got it, the previous owner had already done the following:
1) Chopped rear frame
2) Relocated Battery Box
3) GSX-R rear sets
4) Custom Tank
5) Clubman Handlebars
6) Right side stand
7) Straight exhaust

Over the last year, I've gone the following:
1) All new charging system
2) Replaced clutch plates
3) New Front Master Cylinder (from a CB 750)
4) New Clutch lever (from a 2000 Triumph Daytona)
5) Some new running lights
6) New Brake light
7) New Rear Shocks
8) Rejetted the Carbs. (currently running 122.5 mains and the Needle Clip is on the richest notch)

I've got a number of questions for y'all...

 

[gmayer]

The Bike when I got it.

 

[gmayer]

Current Picture

 

[gmayer]

So... I've been having trouble keeping front brake pressure. It doesn't look like I'm leaking brake fluid from the front caliper, and the brake lines and master cylinder are new. So... I don't really know what the problem is.

Do you all know of any other Brake Calipers that are compatible with a late model GS750?

Also, if I wanted to do a front end swap, any advice on which to go with? Are any modern front ends compatible?

 

[boingk]

Try a brake bleed, it may have air in it. This would cause trouble keeping brake pressure or even total loss of brake pressure once warm. Its also possible the master cylinder has an incorrectly installed oring and is leaking pressure.

Can you give any more detail on what is actually happening?

Cheers - boingk

 

[gmayer]

Thanks man. When I first get on the bike, it usually has okay ish brake pressure. Unfortunately, this tends to fade. I didn't know air in the system would make things worse as it got warm.

I bled the brakes, replaced the master cylinder, bled the brakes, bled them again 3 weeks later, and then replaced the pads.

Maybe I'm not bleeding them correctly... but I really don't see how anyone could screw that up. The last few times I bled them, there was no air coming out of the line. But, I'll go ahead and give it another try.

Also... the rotor does look pretty shiny.

 

[norman1950]

One great failsafe way I have found in bleeding brake is to go get a clear tube with the inner diameter the same as the air bleeder. I believe it is 8mm. First loosen the bleeder. Put the clear tube on the bleeder with a zip tie. Make sure the zip tie is over the "nut" part and snug it up as tight as you can get it with out breaking the tie. This will keep the fluid from leaking from the tube. Now put some fluid in the tube about 2-3" above the bleeder. Put the other end of the tube up and over the bars with open end facing down (NOT TOWARDS GAS TANK OR ANY PAINTED SURFACE IN CASE OF SPILLAGE).

Now that you have the tube on and bleeder loosened with fluid in the tube, pump the brake lever. You will see fluid shoot into the tube, and if there is air you will see the air rise through the fluid. When you release the lever the brake system will suck back in fluid not air. Keep doing this until you get no bubbles when you press in the lever.

If you tighten the zip tie enough there shouldn't be any leaks and you should be able to spin the tube enough to tighten the bleeder until you take the tube off. Now take the end of the tube and try to put it low so that the brake fluid flows to the middle of the tube and away from the bleeder before you take the tube off.

Now just make sure to snug the bleeder back up. Also make sure that your master cylinder is always full when pumping the lever. And do this to both sides.

 

[gmayer]

Thanks Norman!

I had one of those one man bleeder bottles (it has a little attachment for the bleeder valve, clear tube, and a little bottle at the end). Sadly, I've lost it in a recent move. Good to know some 8 mm tubing could also simply do the trick.

 

[slayer61]

The bike is 1077 GS750. When I got it, the previous owner had already done the following: ...
6) Right side stand...
I've got a number of questions for y'all...

Just out of curiosity... Why would one want the stand on the other side? :-k

 

[gmayer]

Just out of curiosity... Why would one want the stand on the other side? :-k

Hahaha! Well, when I'm parked in a long line of bikes, it's kinda fun to stick out.

 

[Steve]

Just out of curiosity... Why would one want the stand on the other side? :-k

Because it's funny as all get out when you have a line of bikes and the one in the middle is leaning the other way.

I knew a guy on a Wing that had a stand on each side. When asked why, he said it's really quite simple. How many times have you had to circle around a parking lot to find a space that is sloped the "right" direction? With two stands, whatever way the lot slopes is probably good, as long as the front wheel is not below the back wheel.

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