95 Jimmy SLT - is there a trick for removing the high mount brake light??

Andrew-thats exactly what happening. Sometimes you can slide a screwdriver in as a wedge and wedge it against the 'wellnut' that's spinning or if all else fails-CAREFULLY

oops...hit the wrong button-sorry-carefully pry the unit up and then once off you'll have to improvise an alternative method of re- mounting the light. Example would be the proper sized nut-glued into the old spot! Good luck JP

Jerry,

Thanks for the direction. It doesn't seem like it will be a cinch to pry this thing up but I'll give it my best shot. What a PITA this has turned out to be. There must be a reason all the other models have the light on the roof itself rather than the glass...

Andrew.

Btw.. I have a super-stupid q for you if you're in the mood. The vac check valve on the vac reservoir under the hood - which way does it operate? I feel like I've had a dose of stupidity - I assume it should let air into the 'ball' to keep positive pressure but not allow it back out??

Hmmm, thats kind of a brain teaser :) Seams you would not want a check valve right at the resevoir because the vacuum/air needs to go both directions.

But, at something like the brake booster you want it to go out so it keeps vacuum at its highest. even when the car if shut off.

Thanks for the feedback Scott. Here's my pseudo-issue... I broke the nipple/air tee that enters the vac ball so I redrilled it and tapped the plastic to fit a brake bleeder screw (following the 'use what you've got mentality). Anyway, it ended up making a fantastic connection but I wasn't certain that I didn't cut out a check valve. When I look at the OEM replacement vac ball/reservoirs, many of them have built in check valves. I know they all have 2 ports but I am still feeling stuck on stupid about this. It's funny that I've torn down motors, brake/suspension systems, etc. but that a damn check vqlve has me gasping for direction. The heart of this all is that it seem that about the same time I modified the ball reservoir, I had vent actuator/blend door issues that seem to coincide with whacky 4WD performance (it would all point to a vac issue and I think it's due to a check valve leading to or coming from that damn elusive ball under the hood).

Thanks again for the help and thoughts. Andrew.

I would guess: if it has two fittings at the ball, one will have a check valve that goes to manifold vacuum, the other without check valve to accessories. This way it can "store" vacuum. Maybe you did drill out the one that goes to the intake manifold....

Actually the ball doesn't have a check valve in it. The valve is on the back side of the manifold between the manifold and the tree of lines next to the distributor. The ball will have one fitting with a line going to it, The check valve allows air through toward the engine (if you apply vacuum on the engine side it should open) The normal vac culprit is the line coming off the engine getting rotten and splitting or just getting loose. BTDT on the 94 and the 97.

Thanks again Steve! I guess I'll see when the new part arrives. I bought an OEM replacement with a built in check valve. I will go try to hunt the one behind the dist down for testing. I can't find a diagram anywhere that references the check valve location/s... MOD, Chiltons, Haynes... Nada.

Take care, Andrew.

On the 95 the valve should be in the line coming off the back of the manifold. If someone has changed the lines in the past they may have moved it farther out from the manifold but it is usually easy to find, just look for a white plastic item the shape of a small fuel filter.

Steve,

When you say manifold are you actually referring to the plenum/intake hose that goes by the distributor? Mine has no such white fuel-filter looking thing attached to it but it cetainly doesn't look like it was ever replaced either.

I have a straight PCV valve that should act as a decent check valve. I will put it in line with this hose and see if my surging issues fade away in the meantime before I replace the vac reservoir.

Thanks. Andrew.

Take a look at the third picture on this AZ guide.

is the 2.2 but it shows the vac ball better than the rest. If you look just to the right of the brake booster you will see the check valve. On the 4.3 it is usually closer to the engine. The next picture shows it but not real clear, just to the right of the number 1 tag.

Steve - now I think I know where you're talking about. It comes directly out of the manifold and looks almost exactly like a PCV valve with a hard line that goes directly to the intake?? I didn't think this line went to the vac ball at all but perhaps that's exactly the point. I didn't realize that the tee there was a check valve. Thanks! Andrew.

Took a couple pics of a customers 97. The lines should be close to a 95.

The blue line is ported vacuum. The green circled item is the check valve. The lines in orange are all connected to the ball through the T on the valve. If you look at the orange circle you will find another T that splits the line again. The lower right goes into the interior for the heat/AC control. The orange line going back across goes to the 4X4 system through the control valve on the transfer case.

Steve,

Thanks a million this is the info I needed for sure! The vac routing is identical to mine. The funny thing is that I can't find a listing for that damn OEM check valve anywhere. I'm sure any 3/16" check valve would work though...

Take care, Andrew.