New Years WE, Part3 - Vacuum Pump Removal

[Gulfsurfer]

This thread is the last I'm posting about my New Years weekend project. Only so much fun a man should have on any given weekend...

I decided to remove the vac pump since I installed a turbomaster WG controller. Less stuff spinnning off the primary drive belt, to one day lock up far away from home. My only concern is that the removal of that pulley between the crank pulley and the AC compressor pulley might contribute to belt slap. We'll see the next time I rember to turn the air on and check.




The pics above show the removal of the pump, not as straight forward as has been written about. Left - The 10mm bolts are not accessible thru holes in the pulley from the front. They are actually behind the bracket and really can't be removed (might have been able to do it with an air ratchet (?). from behind Middle - remove the compressor to allow removal of lower compressor bracket. Right - bracket off, turned around shows vac pump bolts, they were pretty tight BTW.




Pic at left above shows space liberated by removal of the pump. Taken from within the passenger side fender well. Pic at right shows excess stuff removed from engine, less to go wrong!



Pic above: belt tensioner shows pre-run condition (look closely, mark is to teh left of the wear indicators). As soon as I started her up, the mark aligned with the first wear indicator mark. I tried using the 99.5" belt commonly called for sans-pump. No go, too tight, ended up with a 101-1/8" belt.

The combination new injectors, new glows, new 4" exhaust and turbomaster have really pepped up the response of the engine. I've yet to do serious towing to see what the effect will be on the EGTs, but hope to see an overall reduction in temps. This Sub is hooked up to something 95% of the time so I wanted to improve its chances at seeing a long trouble free service life by performing proven mods.

Thx to all the enthusiasts on this forum and other forums for all their knowledge I've been able to draw from.

 

[matuva]

You may do the fan clutch mod to improve prevention of everheating
I found this thread that may help you in (thanks to GMCTD) : http://www.thetruckstop.us/forum/showthread.php?t=12265

 

[Gulfsurfer]

cooling mod

Thanks, I'm pretty happy with the Dmax fan & clutch, when it kicks in, it moves some air!

It seems like I could lengthen the bimetal coil tab about 1/8" and get the clutch to engage a little earlier (?). I'd be OK with 195 engagement (?). Right now it comes in a little past 210 on the dubiously accurate stock gauge. I should actually upgrade that POS gauge to a mechanical gauge also. I really don't want to have stuff hanging from my dash...don't want to sacrifice my loose change pod under the radio though.

I think my next scheduiled upgrade is a remote oil filter mount. It's a royal mess to change filter now (4wd).

You may do the fan clutch mod to improve prevention of everheating
I found this thread that may help you in (thanks to GMCTD) : http://www.thetruckstop.us/forum/showthread.php?t=12265

 

[matuva]

Thanks, I'm pretty happy with the Dmax fan & clutch, when it kicks in, it moves some air!

Yup, I had the one from Heath, nice stuff!

TI think my next scheduiled upgrade is a remote oil filter mount. It's a royal mess to change filter now (4wd).

Good thought. I had one on my ex-rig. That really makes things more simple

 

[fastjohnny]

On my list of things to do...

 

[Green Machine]

Nice pics.

The way you removed your vacuum pump (moving ac compressor and removing the lower bracket) is the only way to take out the vacuum pumps on 94-95 models. Don't know why but thats how they are designed lol.

For belt sizes, you are right. 99.5" will not fit on 94-95 models. Most likely due to the placement of the accessories compared to the 96+. They normally say an 1" less then stock belt size, I think the stock belt size on 94-95 is 102.5" so with the vacuum pump removal I would say 101"-101.5" works. I think i have a 101.5" on mine and it works but i don't remember exactly the size i just am thinking its 101.5...

And when I did mine, I already have a TM but I was finally able to remove all the vacuum lines and sensors and my EGR/put my F intake on . Cleaned my engine bay up quite a bit without having all those extra lines in there lol.

 

[Gulfsurfer]

thx, I had a little time to do the thread and felt I'd give back to the forums for all the info & goodwill I've found here.

The way to really cleanup my engine compartment would be to go with a mech inj system. Don't get me wrong, I'm a huge fan of electronic controls (that's my profession), but I also understand the probability of failure analysis. The more components in a system (like all the 6.5's wiring connections, sensors, etc), the higher the chance of failure...eventually.

The eventually part is what's keeping me from converting. That and all my other projects. Also, Katrina taught me something...uh oh...getting philosophical...live for today.

Anyways, I've got a Kubota 3650 tractor with mech inj and all it needs is to spin the engine & she fires up. After that, no juice needed. a mechanical fuel stop to kill her. A marvel of simplicity.

Nice pics.

The way you removed your vacuum pump (moving ac compressor and removing the lower bracket) is the only way to take out the vacuum pumps on 94-95 models. Don't know why but thats how they are designed lol.

For belt sizes, you are right. 99.5" will not fit on 94-95 models. Most likely due to the placement of the accessories compared to the 96+. They normally say an 1" less then stock belt size, I think the stock belt size on 94-95 is 102.5" so with the vacuum pump removal I would say 101"-101.5" works. I think i have a 101.5" on mine and it works but i don't remember exactly the size i just am thinking its 101.5...

And when I did mine, I already have a TM but I was finally able to remove all the vacuum lines and sensors and my EGR/put my F intake on . Cleaned my engine bay up quite a bit without having all those extra lines in there lol.

 

[NVW]

thx, I had a little time to do the thread and felt I'd give back to the forums for all the info & goodwill I've found here.

The way to really cleanup my engine compartment would be to go with a mech inj system. Don't get me wrong, I'm a huge fan of electronic controls (that's my profession), but I also understand the probability of failure analysis. The more components in a system (like all the 6.5's wiring connections, sensors, etc), the higher the chance of failure...eventually.

The eventually part is what's keeping me from converting. That and all my other projects. Also, Katrina taught me something...uh oh...getting philosophical...live for today.

Anyways, I've got a Kubota 3650 tractor with mech inj and all it needs is to spin the engine & she fires up. After that, no juice needed. a mechanical fuel stop to kill her. A marvel of simplicity.

So true, I have a 59 Fordson Power Major tractor, even the starter bendix is mechanical:smile5:

 

[Matt Bachand]

FWIW 210 on my gauge is more like 217 on my scanner. I'd do the fan clutch mod. Try 1/8th - 1/4 movement and see if you like it. Only takes 20 minutes to make a 2nd adjustment if necessary.

 

[Gulfsurfer]

coil adjustment

thx for the reminder Matt. I hadn't thought to cross check my dash gauge. All I've got is the Gmtd software, at least it'll give me a digital reading.

FWIW 210 on my gauge is more like 217 on my scanner. I'd do the fan clutch mod. Try 1/8th - 1/4 movement and see if you like it. Only takes 20 minutes to make a 2nd adjustment if necessary.

 

[chevyguy88]

Just had the pleasure of spending a fun filled weekend on this type of project myself.

Just wanted to note that it IS possible to take this vaccum pump off without pulling the AC compressor.
Although it is a complete mf to do it I was not gonna pull the AC compressor I REFUSED!
It took me about 2 hours although I do have small nimble fingers.
Used right combination of craftsman and snap-on open end wrenches and box end wrenches to get the top two bolts off.
For the bottom bolt I went under the truck and used a quarter inch ratchet and a cheater pipe. (quarter inch is all that would fit)
Had to use a 3/8" - 10mm (12point) socket on my 1/4 ratchet and a 1/4 to 3/8 adapter to get the "Pefect" spacing to be able to turn the ratchet.

Best of Luck to any who take on this task!

Nice pics.

The way you removed your vacuum pump (moving ac compressor and removing the lower bracket) is the only way to take out the vacuum pumps on 94-95 models. Don't know why but thats how they are designed lol.

For belt sizes, you are right. 99.5" will not fit on 94-95 models. Most likely due to the placement of the accessories compared to the 96+. They normally say an 1" less then stock belt size, I think the stock belt size on 94-95 is 102.5" so with the vacuum pump removal I would say 101"-101.5" works. I think i have a 101.5" on mine and it works but i don't remember exactly the size i just am thinking its 101.5...

And when I did mine, I already have a TM but I was finally able to remove all the vacuum lines and sensors and my EGR/put my F intake on . Cleaned my engine bay up quite a bit without having all those extra lines in there lol.

 

[Gulfsurfer]

The good part of removing the compr to remove the vac pump is that you only have to do it once!

 

[Burning oil]

This thread is the last I'm posting about my New Years weekend project. Only so much fun a man should have on any given weekend...

I thought you said that was your last post?? :rof: j/k
What part of Gulf caost you on?
I have done a few Mechanical ip conversions if you get stumped let me know. One thing I can tell you is GM no longer makes the Throttle cable so you will have to salvage one. or, I happen to have a brand new NOS cable still in the box I would sell.

 

[WarWagon]

My only concern is that the removal of that pulley between the crank pulley and the AC compressor pulley might contribute to belt slap.

Yes it will. You can hear the belt vibration in the cab and see it slap. Higher outside temps (115+ F) the worse it gets with high head pressure R134a. Course this is the 1993 stock belt drive that is the same w/o a vac pump factory. Other than noise you should be fine. I have looked at the possibility of leaving the vac pump plugged and on as an idler pulley to prevent this. Removal of the vacuum pod and discovering it is oil filled for the bearings... Well this is one less part on my engine to lock up as I can live with the belt slap. 1988 454 gassers have an idler pulley under the compressor for the same reason and when it locked up and ruined the belt a shorter belt saved us the cost of a new pulley...

This high head pressure R134a is reason #1 the compressor was moved to the other side of the engine in later years and the long A/C hoses to do so look crazy. The tensioner assy has to have a extreme strong spring to prevent belt slip from the AC compressor starting vs. mentioned later designs.

 

[Gulfsurfer]

I thought you said that was your last post?? :rof: j/k
What part of Gulf caost you on?
I have done a few Mechanical ip conversions if you get stumped let me know. One thing I can tell you is GM no longer makes the Throttle cable so you will have to salvage one. or, I happen to have a brand new NOS cable still in the box I would sell.

B-Oil: What can I say, bored at work...I get to the camp on weekends, in the Bay St Louis area.

WW: I honestly forgot to check for the aforementioned AC belt slap last summer...AC still works tho...I try to live by a couple of Golden Rules: If it ain't broke, don't try to fix it. AND: No good deed goes un-punished.

 

[Burning oil]

I know what you mean about being bored at work. Just noticed I misspelled "coast" above. At least I did'int say: what part of the golf course you on?

Im bored :sleep: and its to cold!! I think its 45* today. Way to cold for humans.