Benford Terex HD850 Dumper - leak from drive motor

[Routy56]

As the title suggests, I have an annoying leak from my trusty old dumper.
About an eggcup full a day but seems to be getting worse

This is the machine which has served me well for a few years now.
Like to keep on top of routine maintenance. So, run it over my inspection pit this morning......

The drip is definitely coming from behind that shiny black cover on the back of the drive motor
Have got both the Workshop Manual and Parts Manual for the machine.
Doesn't give any information about stripping down a drive motor to replace seals
A seal kit is listed in the Parts Manual
All, it says is:
"In all cases involving the disassembly and assembly of the motor you are strongly advised to consult your Poclain Hydraulics dealer."

So, my questions to my forum friends are:

1. Have you had experience with these drive motors or similar?
2. Can a seal kit be done in a standard workshop like mine?
3. Or should I just swap the drive motor and be done with it?

It goes out on site next week to earn it's keep so a quick fix can be done otherwise I'll have to put up with a little dribble

 

[Shovelhands]

I think it’s probably the brake pack leaking? But Ive no experience of changing the seals.
my Terex roller has the same/similar drive motors, I have a parts manual somewhere which may show a breakdown of it?

 

[Routy56]

So having done loads of repairs and stuff on my old dumper, going to sort out this poxy leaking drive motor
Whilst I have no problem tacking a leak and replacing seals, I am unsure about the down time......
.....it's always in demand every week
So one way to go will just swap it out for a good used one, then sort the other out in 'my own time'
Found one such drive motor on eBay - what do you think guys?
Do we know this dealer? Is Tom Lownds one of our members?

 

[Mick-the-fitter]

It normally is the brake pack leaking, is it windy when moving, like the brake isn’t off properly?

 

[Routy56]

It normally is the brake pack leaking, is it windy when moving, like the brake isn’t off properly?

Seems OK but sometimes it's a bit twitchy moving off.
I'll glad have a got at sorting out the seals but what should I order?
Have got the PDFs for workshop manual AND parts list but not much detail about sorting it
On the photo above, is it a question of just removing that steel cover and getting on with it?
On the machine job or on the bench?
Any info before I commit to a repair would be useful

 

[Routy56]

Here's a schematic from my part PDF:

So will a seal kit (item 37) sort it out

 

[doobin]

I reckon it’s them new wheels mate.

 

[Routy56]

I reckon it’s them new wheels mate.

Those wheels and tyres are worth more that the complete machine......
......is this a case of wheel envy

 

[Mick-the-fitter]

The brake is spring loaded and they use hydraulic oil to compress the brake pack off, take the big circling out ( and you will wonder how you get it all back in, not sure what would be in the seal kit, but on rollers, you can order brake pack seals separately, got to take the motor off the dumper and would need a press.

 

[Routy56]

The brake is spring loaded and they use hydraulic oil to compress the brake pack off, take the big circling out ( and you will wonder how you get it all back in, not sure what would be in the seal kit, but on rollers, you can order brake pack seals separately, got to take the motor off the dumper and would need a press.

Thanks Mick - understand what you are saying. Have got a nice press that needs playing with
So I'll order a replacement OR factor in some down time to assess and order the parts as required

 

[Mick-the-fitter]

My question would be why is that cover shiny and black, when the rest is well used! I guess someone has had a go at revealing it already and caught the seal on the way in, they’re a bit temperamental!

 

[GazCro]

The brake is spring loaded and they use hydraulic oil to compress the brake pack off, take the big circling out ( and you will wonder how you get it all back in, not sure what would be in the seal kit, but on rollers, you can order brake pack seals separately, got to take the motor off the dumper and would need a press.

I had a drive motor leak on my bomag roller. I took it off and took it to a local fella to put seals in. From what i remember him telling me about it you access the brake seals from one side but have to dismantle from the other side to get to the seals which were leaking on mine. I do know it's likely any seals you remove will need to be replaced as they probably will have swelled and won't go back in without getting damaged.

 

[Routy56]

My question would be why is that cover shiny and black, when the rest is well used! I guess someone has had a go at revealing it already and caught the seal on the way in, they’re a bit temperamental!

Pity that are not near here....
...so if you are passing and like working on a bench in a nice warm barn

 

[Routy56]

Spent the morning in a nice warm barn workshop fitting the replacement drive motor

Wheel off and windy gun used to undo those 10 tight bolts....

Why is the plumbing so complicated
nearly ran out of butt plugs for all the dripping pipes

Job done and road tested before lunch
Thank goodness I had a nice pit to work in comfort
Feel sorry for poor buggers that have to do this laying on their back on site in thick mud
No leaks and the brakes hold when tested on 45 deg slope - result

 

[T whiting]

Oh yes always easier to do serious maintenance in the workshop/in the yard than in the mud though little fiddly machines tend to get lifted at least to somewhere nicer before surgery.

I'd let the pipes that are dripping drip as long as it's not bleeding at a serious rate it's only the bit of oil in the pipe unless it's a case drain line

 

[Routy56]

Oh yes always easier to do serious maintenance in the workshop/in the yard than in the mud though little fiddly machines tend to get lifted at least to somewhere nicer before surgery.

I'd let the pipes that are dripping drip as long as it's not bleeding at a serious rate it's only the bit of oil in the pipe unless it's a case drain line

Agree with that My brother Graham often laughs at the amount of preventative maintenance that I do on my machines
But I believe that prevention is better than cure. And they have to be totally reliable when out working on site
Tried stop as much of the drips as I could with plugs and a tray. Didn’t want 20litres of stuff from the tank being dumped. My pit has had too much oil in it recently

 

[Routy56]

So having successfully swapped out the drive motor with the leaking brake pack, what do you guys think I should do with the old one
It was working perfectly but dripping an egg cup full a day.
Do I keep it as a spare?
Install a seal kit in it?
Or simply move it on via eBlag as ’spares or repairs’?
Obviously I’ll be very kind to members of this forum who want it

 

[Flying Torquewrench]

I would keep it Dave. At least you will have a replacement in stock in case another drive motor decides that it had enough. Better to get the machine going quickly again and accept a small leak instead of having to wait on a new replacement drive motor whilst the machine can’t be used.

No harm in trying to install new seals in it.

 

[Routy56]

I would keep it Dave. At least you will have a replacement in stock in case another drive motor decides that it had enough. Better to get the machine going quickly again and accept a small leak instead of having to wait on a new replacement drive motor whilst the machine can’t be used.

No harm in trying to install new seals in it.

That’s make sense - can add it to my stock of ‘come in handies’
Like the idea of trying to install new seals in the comfort of my workshop
Now can anyone recommend where I should source a seal kit? ......

 

[V8Druid]

That’s make sense - can add it to my stock of ‘come in handies’
Like the idea of trying to install new seals in the comfort of my workshop
Now can anyone recommend where I should source a seal kit? ......

get 'em out and size 'em up