Lbz trans cooler line upgrades

[CtChevy427]

I FINALLY put the lines in with the new crimp about three weeks ago....So far so good. Hopefully this will be the last time I will have to deal with them leaking.

 

[THEFERMANATOR]

thanks for the heads up on the allison pressure and temps
any idea what causes the 200 + pressures?
I'll see if I can get it modified in the shiftkit

There's nothing you can do to change it. Under most conditions they don't see more than 60 psi, but under certain conditions it's possible. The cooler flow in the Allison is primarily consisted of the fluid bypassed by the pressure regulator. This is why GM added in the G solenoid on LLY+. It reduces line pressure which in turn increases cooler flow, and reduces trans temps at idle in doing so(this is why LB7's don't cool the trans well at idle). The trans is lubricated via the returned oil from the cooler(hence why the trans grenades if you lose a trans line, they run dry instantly), so when it's cold the pressure regulator bypasses large amounts of fluid, only so much oil can flow through the bushings and shafts, and the pressure can spike way up. It's just the nature of the beast.

 

[btfarm]

...so when it's cold the pressure regulator bypasses large amounts of fluid, only so much oil can flow through the bushings and shafts, and the pressure can spike way up. It's just the nature of the beast.

and why my trans lines leave a drop or 2 on the floor from December through February but never any other time.

 

[BIGR]

and why my trans lines leave a drop or 2 on the floor from December through February but never any other time.

That's usually when mine drips the worse, I still have the original factory lines on mine. Dealer asked me if I wanted to replace them for X amount of dollars, I told them I would pass on it unless they could absolutely guarantee that GM had improved the design so that it would not leak. So I just haven't got around to replacing them, I put a large piece of cardboard under the truck in the garage where the lines drip.

 

[RI Chevy Silveradoman]

I replaced 2 out of the 3 lines...
Only the oem line leaks a drop or 2. Doesn't usually make it to the ground though...
I went OVERKILL with my hose replacements. Lol

 

[btfarm]

I was wondering about the kits with a set of hoses and compression fittings on the ends. Seems fairly easy and, frankly, 300 psi or less isn't much

 

[THEFERMANATOR]

I was wondering about the kits with a set of hoses and compression fittings on the ends. Seems fairly easy and, frankly, 300 psi or less isn't much

Mike L designed that kit early on. It's a fairly simple kit that involves cutting right at the old crimps, and then putting the lines on with compression fittings. I'm not a fan of compression fittings, but I don't think anybody has had problems with them.

 

[RI Chevy Silveradoman]

That's the way I did mine...But with big fittings. For a backhoe or excavator...lol

 

[btfarm]

I replaced the main return line a LOOOOOONG time ago with an OEM replacement but the other 2 weren't leaking until a couple 3 years ago.