Possible Transbrake Issue
 

This weekend I raced my girlfriend super comp dragster and ran into issues of inconsistency. When the weekend started I attempted to back the dragster out the trailer and the transbrake wouldn't engage. We tested power going to the transbrake and that was fine so we swapped the Hughes Solenoid HP7498HD for a BTE Solenoid 2498 and walla it worked. The first time run the dragster ran a 4.84 with a 1.08 60' but then first round it slowed to a 4.91 with a 1.105 60'. The dragster should have only slowed .005 so when I got back to the pit i checked the valves and all looked fine. The next morning I made another pass and it ran a 4.99 with a 1.13 60' when it should have ran a 4.82.

Do you think the different size transbrake (BTE 2498) can cause the issue of inconsistent/slow 60's which turns into slow ET's? Is there a way that the solenoid can get stuck in the trans causing it to release slow and inconsistent?

Thanks for any help.

Re: Possible Transbrake Issue
 

It's possible. It moves a machined rod with a return spring when it's engaged. The spring or rod could catch on something. Listen to it. It should give a smart crisp "snap - snap" when it's engaged and released.

Dale

Re: Possible Transbrake Issue
 

I know there are differences in transbrake solenoids, especially when it comes to the amount of plunger travel. You may have to pull the pan and look how far the transbrake valve moves in with the new solenoid. Shim the brake solenoid so that the raised potion of the valve is flush with the valve body when engaged. even slightly out is ok, but to far in is not. Is the mph down a lot also or just slow in the front part of the track?

Re: Possible Transbrake Issue
 

Hi Henry,

The MPH was down a little (1.5mph) but it seemed like the slow et in the 60' correlated to the et in the 1/8th. I ended up pulling the transmission earlier today and took it to a local transmission guy in north Alabama. Nice guy that's been working on power glides since before I was born lol. I'll let you all know what he says.

Re: Possible Transbrake Issue
 

I am assuming that the transbrake is also a Hughes model................If so, you have to have a special length rod to go from the large Hughes solenoid to the smaller BTE type. They have different amounts of travel.
Dan