Think I've mended my KAD32 DPE rams

jparham

jparham

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Hi All,
Various threads on here about DPE rams......and having to buy new ones when all that is needed is new seals/scrapers.
After learning how to do it and making a few mistakes over the last couple of weeks while the boat was out for its annual bum scrub, she went back in this morning and I think the tilt is now steady, whereas before it was gradually creeping in under power.
Will add photos and more details shortly, but I can confirm:
a) It's pretty easy to get the ram apart if the 4 end holes still exist (haven't been chewed by galvanic effects)
b) You can buy a kit of bits (£35) from local hydraulics places (p.m. me if you want the details of who I bought mine from. There's a sales number they can use to duplicate your purchase with mine)
or
c) Some of the o-rings and outer seal are standard parts. So could cost you only a few p.
Can't find a source for the scrapers though....

As I say, procedures, more details and piccys later, but for now, here's my link to photobucket:
http://s870.photobucket.com/albums/ab263/johnparham/DPE Rams/
 
jparham said:
Hi All,
Various threads on here about DPE rams......and having to buy new ones when all that is needed is new seals/scrapers.
After learning how to do it and making a few mistakes over the last couple of weeks while the boat was out for its annual bum scrub, she went back in this morning and I think the tilt is now steady, whereas before it was gradually creeping in under power.
Will add photos and more details shortly, but I can confirm:
a) It's pretty easy to get the ram apart if the 4 end holes still exist (haven't been chewed by galvanic effects)
b) You can buy a kit of bits (£35) from local hydraulics places (p.m. me if you want the details of who I bought mine from. There's a sales number they can use to duplicate your purchase with mine)
or
c) Some of the o-rings and outer seal are standard parts. So could cost you only a few p.
Can't find a source for the scrapers though....


As I say, procedures, more details and piccys later, but for now, here's my link to photobucket:
http://s870.photobucket.com/albums/ab263/johnparham/DPE Rams/
Click to expand...


Congratulations, I hope you're right. Look forward to further details of how you did them.
 
Power trim rams

Hi
Well done sounds like you have found a break through.

I had a couple of mine replaced this season,biggest job was trying to remove them off the transom shield it took the engineer a full day,Volvo supply a tool that you fill with grease and hit with a hammer to remove these pins,but it was a absolute waste of time,the rams themselves were pitted slightly and one had a slight weep on it,I had to pay £299.00 plus vat each for new ones.

The engineer said that it was lucky that the other two had not gone as he said he would have to remove the engines to get the pins out. Did you leave the outer cylinders attached to the transom shield, and just removed the rams themselves or did you remove them completely. Also is there a tool you can buy that fits in the 4 holes to unscrew the end cap in order to remove the inner ram. Do you know if it is possible to buy just the inner rams or get them repaired to save the hassle of removing the engines if the other two went knackered. I now know that coastal rides do reconditioned ones for round about £100.00 but this would still mean the problem of removing the engines to get the old ones off if I went down this route.
 
zingaro said:
Hi
Well done sounds like you have found a break through.

I had a couple of mine replaced this season,biggest job was trying to remove them off the transom shield it took the engineer a full day,Volvo supply a tool that you fill with grease and hit with a hammer to remove these pins,but it was a absolute waste of time,the rams themselves were pitted slightly and one had a slight weep on it,I had to pay £299.00 plus vat each for new ones.

The engineer said that it was lucky that the other two had not gone as he said he would have to remove the engines to get the pins out. Did you leave the outer cylinders attached to the transom shield, and just removed the rams themselves or did you remove them completely. Also is there a tool you can buy that fits in the 4 holes to unscrew the end cap in order to remove the inner ram. Do you know if it is possible to buy just the inner rams or get them repaired to save the hassle of removing the engines if the other two went knackered. I now know that coastal rides do reconditioned ones for round about £100.00 but this would still mean the problem of removing the engines to get the old ones off if I went down this route.
Click to expand...

We had our pitted ram/piston welded and then polished back to "as new" condition. Done by a friend who has contacts in W.Mids back street industries. We are now pretty sure the problem is with one of the return valves. We await further info from OP, re. the mechanics of how he's done his job, with bated breath.
 
Right, as promised, more details:
Tip #1 ===> DON'T undo any hydraulic lines.

Make yourself a 'C' spanner by grinding out a recess on a hunk of scrap steel.
9 inches to 1 ft long, 2 inches wide, 1/8th plus thick. I used 2 x M4 x 20 stainless steel screws in 4mm holes and used M4 nuts to tighten them up. Make sure the screws are long enough to go to the bottom of the holes, but no longer. You want as much purchase in the holes as possible, and get as much turning effect when you belt it.

Support the cylinder on the transom shield (I wedged (held) a transom anode under the cylinder). Hit the end of the spanner with a mallet (normal anti-clockwise for undo). Mine came undone easily - they are pretty well oiled up. I chose to use screws in the holes because the ali casting is pretty soft. Part of it will have corroded away. I figured that the threads from the stainless screw would bite in if I needed to belt it harder. I didn't have to.

Unscrew it a little until you can undo by hand. Don't take it out yet.

On the inside RAM there are two blanking plugs (bolts). Take those out to let the fluid out as you move the ram up and down by hand. If you take the hydraulic lines out, it is a bitch to get them in again. You have to loosen up all the retaining nuts and line them up so very carefully to get them back in. If you need more than finger pressure to turn the nuts, you are cross threaded. I cross threaded one of mine and I had to use drastic means to get it sealed again (PM me if you need to know how)

Undo the end of the ram and pull it out.

You will need a kit of seals, o-rings and scrapers to replace those you have.
Take the ram piston complete into a local hydraulics place to get them to match what's on there. I used Pirtek. They have places all over the UK. Kit was £35.

Don't take the piston apart any further unless you have a clean area to catch all the ball bearings and springs that act as a relief valve if you hit a rock. Lose one and you're stuffed.

There's a white plastic (nylon?) 'support' for the spring. It also acts as a valve when the ram is fully extended Mine was partly broken on the edges. Don't have a clue how that happened as the only time this is used is when your ram is fully out (drive up)...... I carefully dremeled mine so the spring would fit again.

There's an o-ring at the end of the shaft that goes into the piston. It isn't necessary to replace this as it doesn't do anything important, but tell them to remember this one.

The outer seal is an NAK VG(1) 16x24x4 Pirtek supplied me an SS16-24-5-R. This is a standard shaft seal. original was 4mm, replacement 5mm stay with original size if you can, but 5mm is still OK. The NAK doesn't have a spring. The latter does, so make sure it is stainless.

The o-ring on the end seal is a standard o-ring BS026-N70

Both the above are easy to take out and replace and only cost a few pence on the net.

The shaft scraper is an SU22-16-4.5DI-L-P . I can't find this on the web from another source, and this is Pirtek's suppliers number. If you find it, let me know where I can buy it from!
Put a small screwdriver or bradawl in to eek out this seal. Putting the new one in is pretty easy. Cover it with ATF and squeeze it back in.

Lastly the piston has an o-ring under a thin flat scraper ring. Part number for the pair is PC34-28-3.1-210-B-DK108. Again, I can't find this available on the net. You'll have to go to your hydraulic man - unless you can find it - if you do, please let me know!
The thin scraper sits on top of the o-ring. The o-ring acts as the pushing force for the scraper. Small screwdriver or bradawl again to get them off. ATF and slide them on gently.

Then re-assemble the end ball bearings and springs, o-ring on shaft, and do up the bolt.

I put grease on the shaft and scrapers when I put it back in, but you could also use ATF. keep the scrapers turning as you push them in.

Do up the end cap with your home made spanner and you are there!

Put the two hole blanking plugs back in, put another half a litre of ATF in the reservoir.

Pull the drive helmet down so it is within the normal range and operate the ram a half a dozen times (don't take it all the way up or all the way down, just purge some air). It auto purges because the inlets and outlets are vertical'ish.
I made the mistake of NOT moving the helmet and thought the relays had seized....doh!

Put your drive back on and purge a few more times.

And you should be good to go.

Whisper, I can't see anything within the RAM that would cause your problems. It's something to do with the pump. Are you sure one of your relays isn't sticking? Can you hear the pump motor when it lifts?

Go to my original post and the photobucket URL for pictures. Downsizing my photos to fit the forum's upload rules is a hassle....

Good luck!
 
Hi Zingaro, I have PM'd you about the RAM cylinders, but I guess other peeps would like to know.
Don't try to take the cylinders off:
1) The greasy hammer tool probably won't work.
2) Like you say, getting at the rod ends from inside the boat is a bitch (they are retained by an offset M6 bolt). It is possible to take these bolts out and then put an M6 stud in the end of the pin and try to pull out, but you have to be a 5 stone contortionist...
3) The boat next to me had his ram cylinders replaced while I was out. He basically cut the cylinder off the pin, tried heating the pin to move it (not) then put a grinder through the pin and pushed both ends in.......
4) Then you have got to get to them to push them back in......

The reason they don't move with the greasy hammer tool is that there is an o-ring on the outer side to keep salt water out, but not on the inside........so the stainless steel reacts with the cast ali and no matter what you do with that tool it won't move......poor design.

The trick (so I am told) is to buy a tool and knock them out ever year and put them back - but you still need to be a skinny to get at those pins from inside.
 
Last edited:
jparham said:
Right, as promised, more details:
under the cylinder).
There's a white plastic (nylon?) 'support' for the spring. It also acts as a valve when the ram is fully extended Mine was partly broken on the edges. Don't have a clue how that happened as the only time this is used is when your ram is fully out (drive up)...... I carefully dremeled mine so the spring would fit again.





And you should be good to go.

Whisper, I can't see anything within the RAM that would cause your problems. It's something to do with the pump. Are you sure one of your relays isn't sticking? Can you hear the pump motor when it lifts?

Go to my original post and the photobucket URL for pictures. Downsizing my photos to fit the forum's upload rules is a hassle....

Good luck!
Click to expand...

Wow, thanks very much John.
This could be fun!!
 
volvo dpe rams

Great post John,I will print this off and give it to my Engineer the next time I have problems with the rams. Where your rams not pitted,if not what caused your seals to go?
 
Hi Tico,
I have PM'd you the details.

When you say your rams are pitted, do you mean the ram cylinders are pitted? Mine were lovely and shiny except for one longitunal scrape mark, caused by the disintegration of part of the white nylon valve restricter and the spring was making contact with the cylinder wall.....
 
As an update to my post a month ago:

The good news: The starboard drive is fixed! Holds its position.

The bad news: Without my touching it at this year's service, the port drive now won't stay in position. Same symptoms as starboard drive had......

So conclusion - ram seals (piston scraper) wears out.......if you are replacing one pair due to age, do the other pair!
 
Hi All,
As an update to this post, the port rams have been playing up all year (won't stay in any position), so this year I 'tried' to replace the seals/scrapers on this leg - and what a problem I had getting the end caps off!!
The 2 x 4mm pins in the tool I made last year for the other drive would just bend when I belted it.....
After much cussing and thinking, I modified my tool to 3 x M5 allen screws, drilled the 4 endcap holes out to 4.5mm, tapped them M5 (with a screw that I modified to become a tap), and screwed both together snug. Then, with the ram firmly supported, belted the tool hard with a lump hammer once. It was either going to shear the screws or undo the cap. Thank god it was the cap that moved!!
I also found this link to someone elses design of tool if you are interested http://volvopentasterndriverepair.webs.com/apps/photos/album?albumid=5407241

Well, replaced the scrapers and seals and rushed to get it all done for a saturday morning 6:30 a.m. lift in.
Didn't fix the problem......
So it ain't the seals. Must be the pump. I found a website with exploded view of the pump:
http://www.marinepartseurope.com/en/volvo-penta-explodedview-7744470-44-7622.aspx
In this I see there's a '13 - pressure box - 854537' and '12 - delivery valve - 873057'

Has anyone on here tried removing and cleaning or replacing these two bits?

Much cheaper than buying a complete pump I assume....
 
I've have a DPE drive that lifts when engine put hard astern. This started after the rams were rechromed & resealed. After much ar*ing around I'm now planning on temporarily fitting an in-line valve to isolate the pump from the circuit. This should prove whether problem is pump or rams related, though not sure which is better to fix. Also before buying new bits would it be worth getting the pump separately pressure tested?
 
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