TheSamba.com :: View topic - New to the sandrail game, finally got one

Sun Jul 14, 2019 5:16 am

I've been wanting to get a sandrail for a long time. I would always go up in the sand dunes with heavy full size 4x4 trucks and Jeeps, and the sandrails & dune buggies would effortlessly eat us up without even trying. I didn't have a dune ready truck this summer, so I went and picked me up a sandrail (VW style chassis/suspension, not the modern long travel type)

I'm completely ignorant on sandrails at this point, as this is the first one I've ever owned. So I'll have lots of questions as this project goes and progresses.

I've been going over different dune buggy/sandrail forums for the last couple weeks, and this appears to be the best one to join, as ya'll seem to be a good bunch of guys with endless knowledge and insight on these.

Sun Jul 14, 2019 6:04 am

First on the list of repair questions...

It's equipped with dual cutter steering breaks. The previous owner put on new disk brake calipers right before I bought it. Still has air in the system, as you need to pump them twice to get good pedal. What's the procedure for bleeding the brake system with steering brakes?

Sun Jul 14, 2019 10:33 am

Welcome to sandrail ownership! I'm no mechanic, so I can't offer you any technical help. I own one, but haven't driven it yet. (it's a slow work in progress)
Do you have any photos of your machine? I'm sure everybody would like to see what you bought.

Sun Jul 21, 2019 2:41 pm

Wow, 100+ views, and not one single reply on bleeding the brake system, equipped with cutter brakes.

No love here to help a new guy in the neighborhood, or maybe ya'll just don't like steering brakes for some reason?

Sun Jul 21, 2019 4:09 pm

Dual circuit? Single circuit? With or without front brakes? Discs on front or rear? Is it that time of the month or are you always this bitchy?

Sun Jul 21, 2019 5:57 pm

The cutting brakes I had were basically a “pass through” system. By that I mean, the cutting brake merely allowed fluid flow through the controller, much like @ simple coupler in the line. When you pulled on one, it acted like a single circuit master cylinder and sent pressure to the rear brake selected. Because of this, bleeding the brakes wasn’t really all that much different than bleeding any other car.
For that, I always bled nearest to farthest, then started over and went farthest to nearest. Probably wouldn’t hurt to pump the handles a couple times during the process.
Pics are helpful. We like pics!

Sun Jul 21, 2019 6:47 pm

TDCTDI wrote: Dual circuit? Single circuit? With or without front brakes? Discs on front or rear? Is it that time of the month or are you always this bitchy?

L0L... bitchy A heavy flow this month like you would not believe ;-)

Spindle mounted wheels on the front (no brakes) single circuit to a Neal's twin stick cutter brake, to dual piston disc brake calipers on the rear.

Sun Jul 21, 2019 6:52 pm

LOL, I’m glad you rolled with it, welcome to The Samba!

Your problem may be due to the dual piston calipers. The piston in the master cylinder might be too small to properly displace the four separate pistons in the calipers.

Sun Jul 21, 2019 6:52 pm

Thanks Axitech for the clarity on the system. I bled them but still don't get a firm pedal, unless I pump it twice. Thought maybe I was over looking something. I'll give it another shot tomorrow.

Sun Jul 21, 2019 6:58 pm

Also, check for warped rotors or excessive play in the rear wheel bearings. Too much movement in the rotor will depress the pistons & cause an initial pump of the pedal to close the gap between the pads & rotors.

Sun Jul 21, 2019 6:59 pm

TDCTDI wrote: LOL, I’m glad you rolled with it, welcome to The Samba!

Your problem may be due to the dual piston calipers. The piston in the master cylinder might be too small to properly displace the four separate pistons in the calipers.

You might be onto something there. It's just a basic Neal's pedal assembly with throttle pedal and twin master cylinders. One for the rear brakes and the other for the hydraulic clutch slave.

Mon Jul 22, 2019 6:20 am

Trying to think how I bled my first dune buggy with the cutting brakes. One thing is the cutting levers are above all other brake line and so air would get trapped there.

When you pull on the lever is it solid or squishy? Does the cutting brake have a bleeder valve? How old is the brake system and is it an EMPI or Neal or some other brand? Could be quality causing the squishy.

I think what I did was held the lever in the up positions as I pumped the brake pedal a lot-more than a normal bleed, probably used a small bottle of brake fluid every time I bled them.

I do remember when I pushed on the pedal and pulled one of the levers I could feel it on the each end- I just made sure it was a solid pedal/lever and if it was squishy it was the wheel cylinder that needed attention.

Gonna need pics of this VW sandrail...

Mon Jul 22, 2019 6:49 am

If you are sure all the air is out, maybe a 2 psi rpv might help.

Tue Jul 23, 2019 1:54 pm

Lots of helpful tips so far, thanks guys.

And here is a picture as requested

Thu Jul 25, 2019 2:54 pm

My alternator is right behind the rear tires. I didn't like the thought of sand getting thrown right into the housing openings, so I made an aluminum cover to give it some needed protection

Sun Jul 28, 2019 12:20 pm

YDBD wrote: Trying to think how I bled my first dune buggy with the cutting brakes. One thing is the cutting levers are above all other brake line and so air would get trapped there.

When you pull on the lever is it solid or squishy? Does the cutting brake have a bleeder valve? Is it an EMPI or Neal or some other brand? Could be quality causing the squishy.

I have an old 70's Ford 4x4 wrecker, I wonder if I lifted the rear of the rail up, so the caliper bleeders are at the highest point in the braking system, then try bleeding once more. Any trapped bubbles will naturally want to flow up to the top?

Levers are soft, unless you pull them twice then they work, just like the break pedal does. Cutter break assembly has no bleeder. Brake pedal and cutter break system are both Neals (which I assume are decent quality)

Sun Jul 28, 2019 9:29 pm

Sand Slayer wrote: Any trapped bubbles will naturally want to flow up to the top?

Levers are soft, unless you pull them twice then they work, just like the break pedal does. Cutter break assembly has no bleeder. Brake pedal and cutter break system are both Neals (which I assume are decent quality)

That could help-but it will take a LONG time for the bubbles to get there. It might be best to get a pressure system to force the fluid through, I've never used those.

If the levers are squishy that is probably where the bubbles are, so pump those instead of the pedal, make sure the reservoir is full and open.

Sun Aug 04, 2019 12:46 pm

Well we made in into the sand dunes this weekend, with the rail. Weather was great, and we had a blast burning fuel.

Mon Feb 24, 2020 12:24 pm

Iirc I had to pump my cutting brake while bleeding to get the air out.