Simrad HLD200 Mk2L Motor Drive Brushes Replacement

[svHyLyte]

I'm wondering if anyone here abouts has had the experience of replacing the brushes in the drive motor of the Simrad HLD2000 MK2L linear hydraulic drive. On our most recent cruise our normally bullet proof auto-pilot gave up the ghost shortly after we had passed the PNR ("point of no return"). As we had previously cruised many, many years without an "Otto" we carried on but the subsequent two weeks of abjectly lousy weather and rough seas made the absence of a reliable, strong, autopilot a real issue on long "legs" off-shore.

Upon our return, our electronics tech--Steve at Jaytron, in Bradenton, Fla--indicated that the power transistors in our autopilot computer had failed and that such failures were often caused by the build-up of carbon dust in the A/P drive motor due to the wear of the brushes. While he is replacing the transistors, he also suggested I "suction out" the motor to remove carbon dust; and, replace the brushes in the motor for our linear hydraulic drive unit. Looking at the thing (see below), I can't see obvious brush mounting caps and I'm wondering it anyone has dealt with this issue with this drive in past and can offer any incite.

Snaps to follow. Any incite/suggestions/observations will be appreciated.

[donradcliffe]

I've done it on that drive, but don't immediately recall the tricks of getting the motor open. If that black ring is plastic, I'd take it off first, then the end cap held on by the two nuts. I do recall that it wasn't too complicated, and I cleaned up the commutator while I was at it.

[svHyLyte]

Originally Posted by donradcliffe

I've done it on that drive, but don't immediately recall the tricks of getting the motor open. If that black ring is plastic, I'd take it off first, then the end cap held on by the two nuts. I do recall that it wasn't too complicated, and I cleaned up the commutator while I was at it.

Thanks Don. I am not an "electrical guy", even remotely, so I am invariably apprehensive when approaching such matters. Before tackling this, I am trying to chase down replacement brushes as it makes no sense to reinstall the originals if I have to take the whole business apart to clean it out. (Unfortunately getting at this darned thing requires that one nearly stand on one's head in the yachts bustle. A real pain in the neck--literally!)

[svHyLyte]

Originally Posted by svHyLyte

...

Snaps to follow. Any incite/suggestions/observations will be appreciated.

Humm... I just realized that my "puters" insistence on changing my spellings somehow substituted "incite" for my apparently misspelled "insight". Perhaps, however, the post will incite further insights, eh?

[svHyLyte]

Well--I got the drive motor issue resolved. Next...

Is there anyone hereabouts that knows the process for "bleeding" the hydraulics on this drive? We can't seem to extract a response from Simrad's tech department on the matter.

Any help will be appreciated!

[estarzinger]

We had those drives.

I used to have some bleeding instruction (unfortunately gave them to new owner), but they do exist.

I think I remember that you opened the reservoir cap, and then pushed the ram in and out several times (by hand) while topping up the reservoir. Then ran the ram in and out several times by motor. And you were good to go (I think, but it is possible I have forgotten something).

I know there was no need to get extra head pressure beyond what the reservoir provided.

[svHyLyte]

Originally Posted by estarzinger

We had those drives.

I used to have some bleeding instruction (unfortunately gave them to new owner), but they do exist.

I think I remember that you opened the reservoir cap, and then pushed the ram in and out several times (by hand) while topping up the reservoir. Then ran the ram in and out several times by motor. And you were good to go (I think, but it is possible I have forgotten something).

I know there was no need to get extra head pressure beyond what the reservoir provided.

Evans,

Thank you for your note. I appreciate hearing from you and I hope you and Beth are doing well. We always enjoy your articles and, with no disrespect to you, especially Beth's. She's a talented word merchant.

Beyond the foregoing, your memory/prescription is pretty good. Late yesterday I finally, after some time, got a response from a Simrad technician who explained the process. (Evidently there's not a lot of technicians available for customer assistance at Simrad--it's a cost but not revenue center--so I consider myself lucky!).

N'any case, the Tech was familiar with the Drive and explained essentially what you did. It seems the system is "self-bleeding" through a check valve on the top of the pump, forward of the reservoir cap. For the sake of others that may need the information, one ensures the reservoir is 3/4's full of hydraulic oil (the end of a bamboo skewer makes a good dip-stick), closes the fill cap; and, exercises the ram, back and forth (as you described) either manually or via the drive with the manual activation keys on the Control Head. One continues the fill/exercise routine until the drive stops "moaning/howling" and the response to the controls is "good". (He indicated that this exercise may take as long as 45 minutes to complete!) If one over-fills the reservoir, the bleed valve will discharge oil (and make a heck of a mess!). If the reservoir is under filled, one cannot, of course, solve the problem.

The Tech also explained that as the Company discontinued the HLD2000 some while ago, it no longer has the seals kits available for rebuilds, which is problematic. The dimensions of the seals and O-rings are, however, given in the Owner's Manual and, as they were "off-the-shelf" parts are the time, one should be able to obtain generic replacements. That may involve a bit of Brain Damage but, better that than having to spend nearly $2K USD on a replacement drive assembly, eh?

So that's my contribution for the day...

[sailah]

Any chance anyone has details on the actuator seals? I got a "FAIL ACTUATOR" error message today after a sterling history with my Simrad. Once on dock and quiet I could tell the pump was working and trying to shove ram either way using keypad. But I could stop the wheel and pump would still go.

Usually if I grab wheel hard it will fail autopilot and release the bypass valve. But this felt like the pump wasn't building pressure. I checked fluid last season and it was perfect, looked good too.

Since it's a small system that fluid had to go somewhere. I haven't physically looked at it since I ran out of time today but will do that tomorrow. In the mean time planning on looking into replacing seals on cylinder out of precaution since they are at least 15 years old.

Apparently the seals are not available from Simrad any more but my guess is that they are stock and Hercules will have them.

Probably a reach that someone has these written down but would be grateful. If not, I'll pull cylinder apart and measure up the seals and attach part numbers to the thread for preservation.

[sailah]

OK went to boat and found puddle of oil under ram. Appears yard that did some work after my accident may have gotten some "stuff" on the piston rod and it wore out the seal. At least that's what I surmise after inspecting rod closely and finding what looked like varnish. It removed easily and I polished shaft.

I brought entire cylinder home after removing from boat. Disassembly was fairly straight forward.

Cycle rod over drain pan and remove as much oil as possible. This assumes you have removed the hydraulic lines as I have the split model. Either way drain oil.

Remove nuts from tie rod ends and the entire thing comes apart. It will drain oil so be ready.

The piston is staked on the rod with a roll pin. I removed the rod end by clamping in vise and using Knipex Cobra pliers at the very end. My piston doesn't ever extend to the extremes based on wear pattern so I knew I was safe to grip here. You don't want to score the shaft! Now the end cap can be removed.

Using a pick I removed the rod wiper and the oil seal. I left the bushing inside.

Then I removed each of the tie rods from the base end piece they are simply threaded into it. Again using Cobra pliers. Removed both wiper and rod seal.

The cylinder barrel seals to the end pieces with some type of very thin paper gasket material. Haven't figured out what to replace with yet but that's easy.

OK so now we have (2) rod wipers, (2) rod seals, (2) piston seals and (2) "gaskets".

All these can be found on Hercules Sealing website for sub $30 total. Attaching screen shot for part numbers

[sailah]

Regarding the gaskets, I ordered a circular gasket cutter since my largest hole punch is 1 1/4" and would prefer concentric.

Also bought some Buna-N gasket material to play with.

All from McMaster Carr

[rextan]

Originally Posted by svHyLyte

Well--I got the drive motor issue resolved. Next...

Is there anyone hereabouts that knows the process for "bleeding" the hydraulics on this drive? We can't seem to extract a response from Simrad's tech department on the matter.

Any help will be appreciated!

Hi
I have similar drive system and as well cannot find the access for brushes replacement. Wonder how you finally managed to replace the motor brushes

[rextan]

Hi,
I’ve the same SIMRAD drive motor and like to know how did you replace the bushes and what is the part number of the bushes and where did you buy them.

[svHyLyte]

Originally Posted by rextan

Hi,
I’ve the same SIMRAD drive motor and like to know how did you replace the bushes and what is the part number of the bushes and where did you buy them.

Unfortunately, as the drive in no longer made, finding replacement brushes is a real trial. The following is something I wrote to another sailer with a similar question:

Are you sure you need to replace the brushes? I thought so too but discovered that my problem was not with the pump drive motor but with leaking seals on the drive shaft itself which I had to have rebuilt.

N'any case, the brushes are under the black plastic band that is around the end of the drive motor. There is a small Phillips head screw that holds it in place. Once the band is removed, you can see the niches the brushes slide into. Getting the old brushes out is not too difficult if you have good access. At the same time you'll want to suction the drive motor out with a shop vac to get out as much of the graphite dust as possible.

The trial will be finding replacement brushes. In our case, I looked for months before I lucked out when the electronics technician we deal with referred me to an old semi-retired mechanic that had specialized in auto-pilots. He happened to have a set of the brushes in his tool chest that he'd had for years. It was his only set and it was just by chance that he could still find them. (He charged us $90.00 for the set!)

As it turned out, when he pulled the old brushes out they were fine and didn't need replacement yet. Since all was apart anyway, I had him install the replacements and marked the old brushes as to which side they came out of and stuck them in our spares locker.

I wish I could be more helpful but that's all I have. It may be that you have to dismount the drive motor and take it to a good auto-electrics shop where they can cobble up replacements. It's not an easy job but can be done in extremes.

Hopefully the foregoing will be helpful...