Heatercore to transmission problems.

[luminous05]

Hey, I just finally had to replace my heater core in my 85 c10, had to special order the core off of summit so it took a few days to get here, the truck had to sit for about 3 days, and was operating just fine until I parked it, I drove it home, now, after taking that heater box off, replacing the core and putting it all back together, when going for the test drive, it won’t under any circumstance, shift out of first. Hoping I’m not the only person having this issue because it just doesn’t make sense to me. Thanks for any help.

 

[matt4426]

Vacuum modulator hose fall off?

 

[SquareRoot]

I hope it's not a manual?

 

[luminous05]

Vacuum modulator hose fall off?

That was it exactly, this is my first classic truck so I had no idea what it was, but that just fixed it, thank you so much.

 

[sidschev]

rockauto for cheaper parts. just got to wait a few days for parts to arrive , but much cheaper than summit.....