vacuum pump replacemetn/ group 31 mod

[A_G]

gotta replace my vacauum pump this weekend...any thing i should replace with it besides the belt?

Anything i should know about?

as far as group 31 mod goes..do i need to upgrade my stock battery cables, besides the different ends?

and for say i could put 3 under the hood...and isolate one for starting only how would i accomplish this?

im getting a hell of a deal through work on the batteries so why not go with 3?

Anthony

 

[Brianedwardss]

Well, back in 2004 me and a guy hooked up 6 group 31's in an F450 IDI just to see what it would do. I expected the starter to go crazy with all that amperage available but it only drew what it needed and was rated for. So we unhooked 'em in succession to see what the limit of batteries that would be useful was. 3-6 batteries did nothing for us, the starter with all loads turned on didn't crank any faster with 6 than it did with two. (by ear it may have been 1% quicker, but that could have been my imagination too). These were new Alliance brand group-31's with the auto-post (not screw on). I ran three batteries in my last IDI, I mounted the extra battery on the passenger fender right next to the voltage regulator. I only did this because I was getting paid to jump start semi's with my truck (it wasn't a group-31 bat, just a short, very wide group bat with recessed top posts.)

 

[subway]

for the vacume pump use a power steering pulley puller to get the pulley off, a gear puller WILL bend up the pulley.

you can also check the lube in the vacume pump, if it is failing it is probubly to late but there is a boly you can pull out under the diapram to access the lub for the cam and bearings in there.

i just took some pics of the 31's in my 94 this weekend and was planning on posting up the upgrades to my battery cables going to the screw terminal and how they fit but the wifey and kids had different plans for me yesterday. it was a worthy upgrade in my book. my truck spins over so much better now! you a have the older body style so you might get away with the regular battery posts, me i had to upgrade to the screw style posts........darn

 

[rhkcommander]

I expected the starter to go crazy with all that amperage available but it only drew what it needed and was rated for.

Amperage won't speed it up as you learned, takes as much as it needs until saturated. If you overvolted it though it would speed up and then possibly burn something out

 

[Dsl_Dog_Treat]

If they're going in you 91, no mods needed. Just dropped a set of 31's in my 90 this spring.

They are heavy, not sure I'd wanna that kind of weight onto one fender though.

Could always make a battery tray down on the frame rail.

 

[A_G]

If they're going in you 91, no mods needed. Just dropped a set of 31's in my 90 this spring.

They are heavy, not sure I'd wanna that kind of weight onto one fender though.

Could always make a battery tray down on the frame rail.

as far as mod went i was referring to the cable ends. couldnt figure out if i wanted to snip the ends off and solder on some eyelets or get the screw on post adapters or waht.

The reason i want 3 ish, im going to be running a hefty sound system, not saying i want it to have a dedicated battery for that..but it wouldnt hurt.

That and i cant plug in at work, and if we have another few weeks here in oklahoma for sub zero temps i want it to freaking start...

and i get them fore 87.00 after tax for a 950cca

 

[flareside_thun]

Damn Anthony, I'm jealous...don't lemme catch ya in Florida, You'll leave with some AAA core batteries lol.

 

[rhkcommander]

theres some batteries that can be mounted in any direction, i think optima ? well anyway two mounted normal with one of them sideways on passenger side could work. otherwise frame or moving/deleting the overfill/wiper fluid reservoir and making a mount there

 

[Dsl_Dog_Treat]

Just go with the top post batteries and leave the cables alone. they'll be snug but will work with the stock cables.

 

[A_G]

yea but arnt most. group 31s a stud instead of a post...?

they make adapters but iono...lol

 

[crashnzuk]

You can get 31s either way. No need to get studs unless the post type aren't available.
Travis..

 

[rhkcommander]

You can get 31s either way. No need to get studs unless the post type aren't available.
Travis..

x2. napa tried giving me studs so i went back in an told em to swap for posties

 

[subway]

if you cant find the posts they sell adapters at any chain store for a couple of bucks that screw onto the stud making it a post. trouble is they will make the post about a 1/4 higher then a conventional post battery.