FLU419 front loader hydraulic pump issues.

[spalinko]

My unimog front loader hydraulic pump (the belt driven one) is glazing the belt and heating up the pulley. I've messed. With it and it is not wobbly or anything obvious. I cracked the sending line and turned it and it seemed smooth enough but I believe it has gone bad.

I checked the tension, am trying to find full set from napa, sounds doable without tilting the cab?

Is there a modern replacement pump that needs minimal modification to mount?

Should I attempt to rebuild it?

Anyone selling the seal kit P\N 7672633017?

Anyone selling an original?

1994 FLU419
Pump NSN #: 5320-01-241-2454

 

[tennmogger]

Once an old belt, or even a new one, gets glazed, it's going to slip. The V-pulleys get slick too. I have have had good luck scrubbing the pulleys with rough sand paper, and of course change the belt. Yes you can change all the belts without tilting the cab. It takes time to work them over the fan. and yes, the smaller belt will go over the biggest pulley as you work it toward the engine. Then re-tension the belt using the tensioning bolt on the pump.

The belt slippage is the safety on the front system. There is no bypass.

 

[spalinko]

Awesome thank you for replying.

I have ordered new belts and should have done that first (it has been sitting for at least 4 years)

I've been reading; some people have replaced the front loader pump with a 24 volt hydraulic pump. Do you think that would be a good idea?

I am concerned about making sure I don't "upgrade" the pump to a PSI that could burst my lines or seals. There are some signs of dry rot and pitting on the metal connections.

I would remove the loader bucket but I am concerned about the loss of counterweight and stability. Any comments on that?

Once an old belt, or even a new one, gets glazed, it's going to slip. The V-pulleys get slick too. I have have had good luck scrubbing the pulleys with rough sand paper, and of course change the belt. Yes you can change all the belts without tilting the cab. It takes time to work them over the fan. and yes, the smaller belt will go over the biggest pulley as you work it toward the engine. Then re-tension the belt using the tensioning bolt on the pump.

The belt slippage is the safety on the front system. There is no bypass.

 

[spalinko]

I've decided to go with an electric pump, looking for a 2100 psi 24 volt. Will keep everyone updated. Any advice is appreciated

 

[BELinNC]

When I had my first SEE approx 5 years ago I drove it around quite a bit in in different configurations. When I had the front end loader off and backhoe installed it obviously lightened up the front end, but I didn't notice any issues that affected drivability, it was just a bit less ponderous! By then I had installed new tires that were stiffer sidewall construction then compared to the balloon like michelins and that was the best improvement I made for overall stability (and safety in my opinion) regardless of what configuration the truck was in. I think you would be okay operating without the front end loader if you wanted to.
On the flip side I recall the manuals advising against this practice, so consider that as well!

 

[peakbagger]

FWIW there is safety relief valve on the loader crossarm that limits the loader circuit hydraulic pressure. Some folks have suggested cranking up the setting to get more capacity out of the loader and at least one individual claims to have done so. The hoses are not rated for higher pressure. There could also be issues with the actual loader components. I can not recall off hand what the setting it but 2000 psi sticks in my mind

 

[glcaines]

My unimog front loader hydraulic pump (the belt driven one) is glazing the belt and heating up the pulley. I've messed. With it and it is not wobbly or anything obvious. I cracked the sending line and turned it and it seemed smooth enough but I believe it has gone bad.

I checked the tension, am trying to find full set from napa, sounds doable without tilting the cab?

Is there a modern replacement pump that needs minimal modification to mount?

Should I attempt to rebuild it?

Anyone selling the seal kit P\N 7672633017?

Anyone selling an original?

1994 FLU419
Pump NSN #: 5320-01-241-2454

Have you checked with Expedition Imports? They have a large amount of FLU419 parts, a lot more than they have listed online. If it was me, I would keep it original.

 

[The FLU farm]

I've been reading; some people have replaced the front loader pump with a 24 volt hydraulic pump. Do you think that would be a good idea?

I am concerned about making sure I don't "upgrade" the pump to a PSI that could burst my lines or seals. There are some signs of dry rot and pitting on the metal connections.

I would remove the loader bucket but I am concerned about the loss of counterweight and stability. Any comments on that?

I'd leave the simple stock setup alone, just fix whatever minor things might need to be. Like the belt.

If doing an electric over hydraulic conversion it's easy enough to buy a unit with the correct specs. And dry rot on the fittings are a new concept to me, if those are indeed what's rotted.

Removing the bucket is easier than it is to remove the loader, but why cripple the machine??

 

[spalinko]

All right after some talking with Mason Dynamics I could only find a 24 volt pump with like a 3-4 gpm max which would mean my buckets going to be really slow, also it can't be continuous use otherwise it would burn up so it would have to be hooked up to a hot switch or switches on the levers.... I haven't disconnected the pump lines or anything, just cut the belt off, and I have new belts so.... I'm going to try to clean up the pulley, give it a little bit of texture And hopefully that's all it needed, there was some squealing as well as heat coming from the pulley so I am a little concerned I'm going to have to try to rebuild that bearing and packing.

Right now we're in the middle of a bit of a water damage emergency and we absolutely need the backhoe, the front loader is held up by safety locks right now. That's the only reason why I was contemplating removing The bucket just so we could continue using the excavator.

I have checked expedition imports and they have been incredibly helpful but front loader hydraulic pump is just one of the few things that they don't have or a rebuild kit for it such as the bearings and seals at least that's what I've found.

 

[The FLU farm]

If you're hell bent on not using the stock pump, you could run a 12-Volt pump instead. Off of one battery, of course.

But don't you think that these stock pumps can take a little heat? After all, some SEEs were deployed and used in much hotter weather than even Phoenix has to offer this week. I doubt that the ones that made it back to the USA all had damaged pumps.

 

[peakbagger]

I see stock pumps for sale on Ebay out of Germany Frequently. Or try Atkinson and VOS out of England. I believe but have verified that that pump was supplied by Mercedes Benz out of the factory and was not an upfit component installed in the US. Its a pump made Eckerle in Germany. My experience is that hydraulic pumps are fairly easy to rebuild unless someone ran some junk through it.

 

[spalinko]

I haven't put the belts on yet I'll probably get around to that tomorrow but here's a picture of the original pump as it's hanging right now

I haven't finished removing the pulley, I'm going to see what I can see and clean it up before I put the new belt on

 

[peakbagger]

I haven't put the belts on yet I'll probably get around to that tomorrow but here's a picture of the original pump as it's hanging right nowView attachment 901744View attachment 901745

 

[peakbagger]

Yup thats the one I see on sale on German Ebay on occasion.

I think they go in the $500 range.

 

[spalinko]

Excellent I'll take a look right now! Thank you

Yup thats the one I see on sale on German Ebay on occasion.

I think they go in the $500 range.

 

[peakbagger]

A quick look at Atkinson and Vos in England shows several options. Hydraulic Systems | Atkinson Vos (unimogs.co.uk)

They are usually easier to deal with than the German sellers. Note the English calls the 406 series a U900 a SEE is the end of the 406 series so it may have the 1300L pump.

 

[spalinko]

All right so I found it!! I can't believe I never was able to find an eBay through America....

Hydraulikpumpe MB Trac 700 MB 800, MB 900 IPSF3-16 144, IPF3-16 144 Ori. Eckerle | eBay

Wichtige Hinweis! OEM: Vergleich-Nr. Der zulässige Dauerbetriebsdruck liegt mit 230 bar nun über den ab Werk verbautem pumpen. Damit ergeben sich weitere Leistungsreserven für Ihr Fahrzeug. 100% Original Eckerle Innenzahnradpumpe.

www.ebay.com

Yup thats the one I see on sale on German Ebay on occasion.

I think they go in the $500 range.

 

[peakbagger]

For some reason, the Germans rarely ship to the US thus the Atkinson Vos suggestion AV is in England. The alternative is to use a reshipping service. The package gets sent to German address and then is reshipped to a US address. It works but costs more. I have bought several large items from AV and as long as they can air freight it, it goes well. They also break up used Unimogs and on occasion sells used parts.

 

[spalinko]

Yeah now that I know exactly what I'm looking for I'm finding some available ones quite the price range anywhere from 600 to $1,400 not including shipping and handling

For some reason, the Germans rarely ship to the US thus the Atkinson Vos suggestion AV is in England. The alternative is to use a reshipping service. The package gets sent to German address and then is reshipped to a US address. It works but costs more. I have bought several large items from AV and as long as they can air freight it, it goes well. They also break up used Unimogs and on occasion sells used parts.

 

[The FLU farm]

Wouldn't it be worth trying to put a correct belt on the pump you already have?