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79DieselScout
06-23-2010, 03:53 AM
I have a 79 Diesel Scout that sat for who knows how many, but had to be too many years.

I think it may have been in some water, too.

The latest problem I've had is the alternator. I've never seen an alternator w/ a vacuum hose off the back of it. Anyone know the purpose? Can it be replaced w/ another alternator? Should I just take this one off and have it rebuilt?

Anyone want to buy a 79 Diesel Scout? Just kidding on that one.

DJC

Ted_Olmsted
07-07-2010, 04:16 PM
That vacuum pump is for your power brakes. The simplest fix is to work with the stock unit or find a similar Hitachi w/ Vacuum pump from a truck wrecker.

I upgraded mine from a Nissan box truck w/ a 90amp model that has a larger vacuum pump. Had to make a new mount to bolt to the engine but it was worth it.

lindstromjd
07-14-2010, 04:55 PM
Better upgrade (but more costly and requires more modifications) is to use a Hydro-boost system that runs off the power steering pump. I did it, and my power breaks work amazing now. No more of that use them two or three times and run out of vacuum crap anymore.

lindstromjd
07-21-2010, 03:30 AM
i have a 1980 diesel scout II and my alternater seems to have stopped charging these past few days.....and my brakes do not work....i have only had the scout for about a week now....the brakes did not work when i got it...could my alternater be the cause of brakes not working?

Alternator wouldn't have anything to do with the brakes themselves, only the power booster. So if you have to stand on the pedal and push with everything you've got just to get anything out of them, then your vacuum pump isn't working. If you push the pedal and it goes to the floor and you don't have any brakes at all, then it's a brake problem.

Allan E.
07-21-2010, 08:23 AM
What drives the booster and the vacuum alternator? Same thing?

bluescout
07-21-2010, 10:37 AM
The alternator is driven by a belt. The vacuum pump is bolted to the back of the alternator and driven by the alternator shaft. The vacuum produced by the pump powers the brake booster.

lindstromjd
07-21-2010, 12:47 PM
The alternator is driven by a belt. The vacuum pump is bolted to the back of the alternator and driven by the alternator shaft. The vacuum produced by the pump powers the brake booster.

Yup. Wierd, rare set-up. Not really worth a crap, either. Mine never worked right anyway though. Only other vehicle I know of that does the same thing is the Chevy LUV with the Isuzu diesel in it.

lindstromjd
07-22-2010, 04:03 AM
could i put a different type alternator (FORD chevy dodge ) with a one wire setup with one hot wire goin straight to my +post on battery and brakes work properly? or would i have to change somethin else?

Yes, you could do that. You just won't have power brakes unless you change to a different system. I love my hydro-boost system that I upgraded to. I would highly recommend it.

lindstromjd
07-23-2010, 02:29 AM
Hydro-boost was the answer to not being able to get a good vacuum out of a diesel. It's a hydraulic brake system run off the power steering pump. I picked mine up for 200, used out of a 1986 Chevy with a 6.2 diesel. If you have any junkyards around, you might even get it cheaper if they don't recognize exactly what it is.

Parts you'll need to make it work:

-power steering pump
-steering lines
-pressure and return lines to booster
-brake booster / master cylinder

You'll also need to fabricate yourself a new tension mount for the steering pump to work, and you'll need to re-route your lower radiator hose. Not hard, but requires some creativity.

You have two options for making it fit on the firewall.

Option 1: The booster itself bolts right up to where your old brake booster went, but you'll have to drill out the holes to get rid of the threads on the firewall. Then you'll need to shorten the plunger rod to fit your brake pedal.

Option 2: Figure out exactly how far out the new booster will sit if you keep the plunger rod it's original length, then fab up a "spacer mount" to fit between the booster and firewall.

Ted_Olmsted
08-09-2010, 05:19 PM
Yup, if you're inclined to pay up for hydroboost, you'll probably stop quicker and you'll be free to fit up a much better alternator of your choice. Still some fab work to make a bracket for the alternator but you'll be charging and stopping like a winner when you're done. Good luck - keep at it.

bobgengeskahn
08-13-2010, 07:38 AM
I had/have the same problem on my 1980 diesel terra.

I installed an aftermarket alternator and an SSBC vacuum boost kit like this one:
http://www.autoanything.com/brakes/69A3151A0A0.aspx?kc=ffproduct

Breaks work fine, but the problem that I have been having is with the alternator. It hasnt been kicking over unless I way over-rev the engine. Is there a simple way to re-tool the pully? or would it just have been easier to get a replacement alternator like what was suggested in the first posts? and if so, are there any particular models that would work in the scout? The reason that i went with the SSBC kit was because I couldnt find any alternators with the vacuum pump on the back... maybe I was just looking in the wrong places...

Jim
08-14-2010, 02:50 AM
Ive got nothing against the aftermarket route and probably would have tried something new if I had the chance or knew more what my options were. We stayed with the stock set up and rebuilt it. We had a local auto electric shop take care of the alternator and we got some new vacuum pump vanes from Jesco. Our local shop was very reasonable and the entire rebuild including pump was less than $100. The alternator got new bushings and brushes. The brakes work great with 32 x 11.5 tires. It really comes down to being able to find a good local auto electric service that will be willing to help.

bluescout
08-21-2010, 06:11 AM
I did mine WAY back in the mid 90's. I cut a unit out of an Olds wagon with the line ends. I took my high pressure line and cut that in half so I'd have all the ends to have custom hoses made. I put a T in the return lines back to my original pump. No change to the pump or radiator hose. My original MC bolted to it but I needed to make a new "pushrod" spacer. I haven't touched a bolt or line on it in 15+ years.

Then I made a bracket and put in a 78 amp alternator.

larrybuck
10-28-2010, 03:56 PM
HI! I'm a brand new nuebieee here. It sounds like you are getting plenty of good advice. I can't offer any, but I.m here struggling w my 1st post. I'll ask you and anybody else who will join in....What info can anybody tell me in real life applications about the sd-33 and sd-33t engs.? I only found out today that they came stock in some scouts. I did't know sd-33's existed on the planet until I went to a car show and bought an old Hot Rod Yearbook, circa 1974 inside of which I found a swap story where a guy puts the 33's in Pinto's, Duster's, full sized Dodge AND Chevy pu's. The article raves about the outstanding mileage, ( 32mpg full sized pu's to high 40's w Duster to 50 w the Pinto) and the long life and torque! How do scouts do? Obviously, the app. w probably be easier w conventional rear drive; heard about any front whl. drive smaller cars w this? I see that it appears that Jesco stocks these engs. and parts etc.... The pictures of a low tech simple small dimensionally eng, seems very appealing, if adequate prts. remain around to jutisfy? the risk of experimenting w this. I'm kind of old school about liking simplicity, thinking of a lot of car swaps, not to mention; trucks! I have had a 82 vw Quantum station wagon 1.6 td that returned mid 50's on road trips, never getting much below 46mpg in every day life. I now have a 85 6.2 fwd Suburban, freeway, mid 20's. Drown me w sd33 info; pleeeease! somebody!

Jmattj
10-30-2011, 07:41 AM
That vacuum pump is for your power brakes. The simplest fix is to work with the stock unit or find a similar Hitachi w/ Vacuum pump from a truck wrecker.

I upgraded mine from a Nissan box truck w/ a 90amp model that has a larger vacuum pump. Had to make a new mount to bolt to the engine but it was worth it.

Ted, do you have a picture or diagram of the wiring?

Scout4BTA
10-31-2011, 10:57 AM
snip,,,
Drown me w sd33 info; pleeeease! somebody!
IMHO, SD33 and SD33T's are old, real old technology. There are no local parts availability. The SD33 are woefully under powered, and the SD33t's have a short life span, due to piston cracking.
A Cummins 4BTA 3.9l or a Isuzu 4BD1T/2T will serve you better.

williampbenton5
12-15-2011, 03:15 PM
Thanks for the info.

Jmattj
02-25-2012, 01:16 PM
That vacuum pump is for your power brakes. The simplest fix is to work with the stock unit or find a similar Hitachi w/ Vacuum pump from a truck wrecker.

I upgraded mine from a Nissan box truck w/ a 90amp model that has a larger vacuum pump. Had to make a new mount to bolt to the engine but it was worth it.

Ted, did you have to use longer belts with this setup? I modified the stock bracket to fit an Isuzu NPR alternator, but the stock belt won't fit around the pulley anymore. I'm thinking of welding up a bracket like yours. Any chance you'd be willing to sell me a copy??