Ls85 pump operations

[Loadstar]

Hi Guys....Finally going to check out the Ls85 talked about in a earlier post. The question i have is whats the procedure for engaging the pump? Theres no water in the tank and the condition of the pump is unknown......would like to see if the pump engages........only for a couple seconds...Thanks....

Edited September 9, 2012 by Loadstar

[bulldogboy]

Most "L" models have an outside lever on the pump panel with three settings: "Road", "Prime", and "Pump". The procedure is to set the parking brake, put the transmission in neutral,

then exit the cab and put the lever into prime or pump, depending on what you need to do, then put the transmission into the highest gear (usually fourth). You should hear the engine

speed up and the speedometer and tach move. Now, having said that, it looks like in your picture the truck may have a lever inside to the left of the driver's seat (the photo is dark

but it looks like a lever next to the seat). In that case, set the brake, transmission in neutral, then lift the lever (there should be a lock to hold it in place), then shift the transmission into

the highest gear. Most "B" models and I'm assuming later "L" models have this interior lever. There will be a primer button on the pump panel. Be sure NOT to run the pump in a dry

condition for long because you will do serious damage to the pump. If you can, put water in the tank, then prime the pump before you start to flow water. Been a long time for me

since I operated "L" and "B" model pumpers.

bulldogboy

[Loadstar]

Thanks Bulldogboy that will be a big help when checking her out! I was also told driving it home....A couple hours or more.... would'nt be an issue....What do you guys think? Top speed must be around 45mph..........

[bulldogboy]

Yes, that's about right on the top speed. These things are not speed demons; they were built prior to the Interstate highway system and were intended for responses around town plus the

motors of that era were not as powerful as they are today. A sunny day, driving a semi-cab Mack fire engine down the highway; doesn't get much better than that. You will get lots of

looks from passing motorists (plus a few curse words because you are only doing 45 MPH). Hope that the seller gave you good advice on the truck's ability to make it home. Good luck

with this truck.

One other thing about the pump set-up, before I get in trouble with the safety guys, don't forget to chock the wheels. We never did this in the "L" and "B" model days but today if you

forget the chocks, look out.

bulldogboy

[1958 F.W.D.]

Bulldog boy is partially wrong about one thing- the transmission is placed into the "direct drive" gear for the pump, which is usually 4th- NOT THE HIGHEST GEAR.

Look on the dashboard somewhere, there should be a tag that says "PUMP DIRECT DRIVE 4th GEAR" or something to that effect.

I would test the pump by doing two things:

1. Activate the primer for about 20 seconds, and watch the suction gauge. You should see the needle approaching the negative readings. If and when the needle comes into the negatives, let it go as low as it can, and then let off the primer. See if and how long it holds. The longer it holds the tighter your pump is (hence good.) If it does not drop into the negatives or does not hold, it's not necessarily the end of the world but it aint good either. Worst case is you wont be able to prime the pump to pull a draft.

2. I would try to get a few hundred gallons of water into the tank, and then "circulate" some water- open the "tank to pump" valve and then open the "fill tank" valve and spin up the throttle until you have about 75-100psi showing on tne master pressure gauge. Let it flow for a few minutes while you observe for massive leaks. There will always be small ones, and dripping from the packing around the main shaft is actually a good thing.

[Loadstar]

I hope the owner knows what hes talking about to........he said they use it often for parades and fundraisers.....but making the trip does concern me a bit.....on the other hand you only go around once !

[Loadstar]

Thanks Fwd......more great advice........assuming it has a tank still....is there a way to look in the top of the tank like modern trucks? I know its not a very big opening but i would be nice to at least peek in. The current owner has never done anything with the pump or tank....

[bulldogboy]

I was basing the transmission selection on the "L" and "B" models that I operated: the "L" models pumped in 4th gear and the "B" models pumped in 5th gear.

In all cases it was the highest gear for those engines. FWD is correct, make sure that you know the proper sequence for your particular engine. You don't want to

have a scare like Joe in Yocum Creek, KY. had with his "CF". I operated these engines 40 years ago so some of the details may have been lost in the haze but

I think I'm pretty accurate on how our particular engines worked. Oh well, off to the Bruce Springsteen and the "E" Street Band concert.

bulldogboy

[twostickmutt]

I hope the owner knows what hes talking about to........he said they use it often for parades and fundraisers.....but making the trip does concern me a bit.....on the other hand you only go around once !

make sure your pump transmission has gear oil in it before driving it home. there should be a dipstick on the pump trans. to check it. if i remember right it is on the right side of the pump trans. hate to see you burn that up. to check for vacuum leaks when priming you can also take the steamer cap of off the pump put a little grease around the pump snout turn the steamer cap around backwards and pull the primer valve handle (with pump trans. in prime) if no leaks the vacuum should hold the steamer tight to the pump for a short time. just dont let it crash to the running board after the vacuum goes away.

[609albert]

everyone right about pumping , don't run pump without water, chocks are good too,

Also you have to double clutch most, when shifting the r.p.m.'s have to be kept low for a good shift, start out in 2nd gear. same with downshifting low r.p.m. .Our LS can do 60 ,but I drive it on the open road around 50. slow is safe and these trucks are old and you have to stop..... even though we rebuilt the brake system totally.

also down the road you might want to install an electronic module in the distributors to replace the points.

[1958 F.W.D.]

twostickmutt brings up a good point. If there is not a dipstick for the transfer case then look on the side of the casting for a pipe plug, also for a line in the casting with the words "OIL LEVEL." The oil should of course be at least this high. Remember it is critical even if the pump is not or has not been used as the truck still drives through this transfer case. Fill with gear oil.

Also, before you check the pump, make sure all the caps are tight- discharges and steamer (intake) caps.

[39 Baby Mack]

The last old Mack I pumped was a 1941 Type 55 and that was over 30 years ago but one thing I do

remember was that It had a small tank on it for oil to prime the pump. I don't know whether the later ones had this or not.

We used to use gear oil in it.

Ron

[Loadstar]

If the things work out I would certainly take my time driving home.....As for the pump I just want to see if it will engage....twostickmutt mentioned pump oil.......what would be the best oil for this so I can bring some with me? Also I was reading he build sheet last night and it says it has a 12v electrical system.......any issues if I had to jump it? Thanks

[1958 F.W.D.]

standard gear oil for the transfer case. NOT TO BE CONFUSED WITH PRIMER OIL which can be any old crappy 10W40 or what have you.

[609albert]

I use cooking oil in the small side tank for the primer oil ,cause it goes out on the soil or roadway.(now we don't want a haz-mat issue).most all macks have or had a positive ground system,just look at the battery-batteries under the officer seat,find the what is wired to the frame, + or -. I think orginals use a 6volt battery connected together for 12 volt. If you have to jump start connect + to+ and - to - , don't let vehicles touch. I think I sent a photo to you of my 54 Ls85.

Just a side note ,if you want to see a neat Ls,google hoot gibson 52 mack, Isaw this truck on a visit to AZ last year.owned by alan brunicina ( past F.C. of phoniex FD) it has a Hall -Scott engine 1000c.i. the hood is 11" longer than a Ls85

[Loadstar]

Pumps went in fine.......only had them in for a second......plaque on the dash read "pump in direct drive" Under that it read "direct drive 4th gear"...............but at the pump panel....the plaque read pump in 5th? Im sure once i get it home i'll have tons of questions.......but you guys were right on the money as far as what to do........Thanks

[1958 F.W.D.]

Loadstar- First thing. Right now, immediately if not sooner when finished reading this post- get on your email, and send an email to Dale R. Guth at mack.museum@macktrucks.com with the serial number, and tell them you just bought the truck and request copies of any and all files on it. Do it ASAP because as of last week when I filed a request, I got a reply that they were on an 8-week backlog!!!!! Best of luck to you with the new toy.

[Loadstar]

I know.....I'm not listening.....but I have all the build sheets, original pictures, specs on the pump and a few other papers about the truck.....the previous owner got the info from the Mack museum.....is this what your talking about? Can you still get a manual for truck? I'm emailing that person right now.....sorry for the delay!!!

[1957B61Vt]

Do you have any other photos of truck?

would be nice to see it . Steve

[Loadstar]

What do you guys think of the crushed fender? Also curious what the holder in front of the fender is for.......Looks like Maybe 2 donut rolls? sorry if the pictures are sideways or repeated...

[bulldogboy]

Loadstar:

The left rear fender doesn't look too bad; I've seen them worse, especially when they get chewed up by a broken chain. You are right about the holder in front of the

fender; it is to hold a soft suction hose to connect the pump to a hydrant. Looking at the pictures, the truck seems to be in great shape. Congrats and good luck.

bulldogboy

[firemack296]

The fender doesn't look too bad. S**t happens to firetrucks too. The holder in front of the fender looks like a holder for a 4 1/2" soft suction hose. The two boxes on the officer's side aren't from the factory tho they could have been installed by the dealer. Everything was an option with Mack other than the basics. They even charged extra to cut off the roof to make an open cab.

Some folks get all waxy about the truck having to look like it did when it was delivered however most judging at SPAAMFAA events allow that any modifications made to the apparatus while it was in service are considered original in terms of judging. Just imagine how many people could restore a 707C to a B Model that has had a diesel installed while it was in service.

BTW, the gold leaf striping on the body looks like original, if not original, when it was redone they reapplied the exact same corner fuer d' lies (fancy corner thingies) as the factory used.

That reminds me, are you a SPAAMFAA member?? If not, you should consider it. There are a couple of Chapters in MA that are active plus one or two in CT. Check out their web site at www.spaamfaa.org for more info. Their publications alone are worth the membership price.