Hey guys,

I've had this truck a little over a year and have been doing minor repairs to it (power steering replacement, rear axle repair etc...) with particular emphasis during this post on the vacuum tree. I've broken my MAP sensor twice (after stalling in reverse, in the cold, both times) and both times the nipple on the sensor was broken off. Today, I got stuck (in 2wd, I live in Alaska and it's break up season) so naturally I got out, locked my hubs, put it in 4wd, and backed it up. While I was backing it up, it sounded like my tires kicked something up under my engine and then my truck stalled out. I turned it back on, my check engine light was on. My first instinct was to check my MAP sensor (the only reason my lights came on in the past) and the hose was disconnected, but nothing was damaged. I reconnected it, got out, and parked it. On further inspection, I noticed several other hoses were disconnected so I just put them back where they were, but one stood out in particular. I looked up the part number on it and got back "Air System Check Valve" which leads us to my posts focus:



1: Label 1 is my Air System Check Valve
2: Is a hose that connects to it

First question:

Is 2 supposed to connect anywhere else? Did something part of 2 get ripped off or is it supposed to sit like that?

Second question:

Why does my MAP sensor keep breaking, or otherwise become disconnected from the tree, when I stall it in reverse?

Any help or source references is greatly appreciated!

 

#2: Stalling probably creates an "air hammer" effect, similar to water hammer when you turn a faucet off or close a valve too fast. That might be what disconnects the hose from the tree (if I understand your question correctly). Maybe try replacing the hose with a new rubber one.

Edit: removed misinformation

 

I think it goes to your cat. Mine is different (1995) but it looks like you have a hose from the air pump to the valves and a hose from the valves to your AIR injectors on the head.