Those useless Jamar park-loc valves!

RT · Post by RT » Wed Jun 09, 2004 9:02 pm

Like so many who have gone before, I thought one of these valves would be a good idea for parking. What a pain in the ass these valves are. With anymore that light pedal pressure, they won't release. The harder you push on your pedal, the more you pressurize everything but they still won't release. You wind up having to crack a bleeder to release the brakes.

I'm thinking of trying to score a medium (3000 psi) ball valve and plumb it in parallel. Its that or junk it. Has anybody done this?

rooster · Post by **rooster** » Wed Jun 09, 2004 9:12 pm

Yes. I used a neoprene ball type brass valve. It was working pretty good so about 5 other guys got them also. Within a year all of the valves started leaking through the top. I had to put a spare parklock back in mine in the woods to get back and it is still there UNUSED. Now my parking brake is a rock, stump,log or a friends buggy.

honegod · Post by **honegod** » Wed Jun 09, 2004 9:43 pm

howcome nobody is bolting a bicycle cable operated disk brake onto a CV joint and using that as a parking brake ?

vwfye · Post by **vwfye** » Wed Jun 09, 2004 10:18 pm

i have the opposite issue... my park loc, after 15 uses quit locking the brakes... grrrrr

Hotrodvw · Post by **Hotrodvw** » Thu Jun 10, 2004 7:54 am

DO NOT use a ball valve for brakes.!! Yes they are SS balls w/ teflon seats, but most ball valves are only rated for 600 psi, a fraction of your brake system. I guess you need to ask yourself....how valuable are your brakes to you when you need them most?? You don't want them failing on you. If you're using a hyd e-brake setup, obviously you'll have no back up in the case of a failure!

RT · Post by RT » Thu Jun 10, 2004 5:14 pm

Cheapo brass ball valves weren't my first choice. I was thinking of something better. There are medium and high pressure ball valves. For instance, Fairview Fittings makes a stainless 3 pc high-pressure ball valve with 1/4" female NPT ends that has a working pressure of 5880 psi. p/n BVSS2403-B. Now, as long as it's available and it isn't two arms and a leg...

It never occured to me to simply replace the Jamar with the ball valve. That seems a whole lot more simple than a parallel circuit with the ball valve just to release the pressure. It would work as well.

Hmmm, I believe we have an account with Fairview at work...

Hotrodvw · Post by **Hotrodvw** » Thu Jun 10, 2004 6:38 pm

Your'e prob thinking of carbon steel ball valves or ss. You won't ever see me do it!

Guest · Post by **Guest** » Fri Jun 11, 2004 4:31 pm

I've never had a parkloc but i thought they were just for burnouts.

RT · Post by RT » Fri Jun 11, 2004 6:10 pm

I've never had a parkloc but i thought they were just for burnouts.

You might be thinking of a line-lock. I would think they're designed to release pressure at the valve. Once applied, the Jamar Park-loc's need the brake's reapplied to equalize the pressure and then they pop up. Hardly a good design for burnouts. Actually, a lousy design for anything...

I ordered a ball-valve today. The 7250 psi version just over $30 bucks Cdn. The smallest it comes is 1/4 female NPT so I'll probably bush it down and run 1/8" NPT to 3/16" inverted-flare adapters. At 6 times the highest pressure this system will likely see, I'm not going to lose sleep worrying about a leak at the stem.

Hotrodvw · Post by **Hotrodvw** » Fri Jun 11, 2004 6:11 pm

Well, you're thinking of a line-loc. It usually has two wires for a remote button to set it, instead of a push/pull knob. Same idea though.

rooster · Post by **rooster** » Fri Jun 11, 2004 6:11 pm

Yea, me and my buddies are pretty much burnouts.

RT, I guess I should have said it a little better. The valves we used were a high pressure brass valve with a stainless ball and teflon seats. I think they were rated at around 5000 psi. They still would NOT hold up.

rooster · Post by **rooster** » Fri Jun 11, 2004 6:25 pm

I have something here called a lever lock made by MICO model# 02-640-008. It is designed for supplemental short term parking brakes. This even has a bleeder on it. It works about the same as a park lock only with a lever. I was told this is the way to go by some of the local off road racers.

RT · Post by RT » Fri Jun 11, 2004 6:30 pm

If they were brass with teflon seals, they would be low-pressure for air and fuel. Depending on brand, 300 to 600 psi.

RT · Post by RT » Fri Jun 11, 2004 6:51 pm

I have something here called a lever lock made by MICO model# 02-640-008. It is designed for supplemental short term parking brakes. This even has a bleeder on it. It works about the same as a park lock only with a lever. I was told this is the way to go by some of the local off road racers.

Yeah, those look like they might work. Particularly the Twist lock #03-640-075 (for harsh environments). They don't look cheap!

Hotrodvw · Post by **Hotrodvw** » Fri Jun 11, 2004 7:28 pm

RT wrote:If they were brass with teflon seals, they would be low-pressure for air and fuel. Depending on brand, 300 to 600 psi.

Correct......most brass ball valves are rated for 600 working psi for WOG.....Water, Oil, and Gas. If you stab the brakes, you can see 2k psi!