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Hydraulic Control Lever Broken

Posted: Sat Jul 06, 2019 11:07 am
by Colin6224#2
Hi
I have a 1974 990 with weatherframe cab.
The Hydraulic Control Lever has broken off due to metal fatigue. The break is close to the hub of the lever and can't be fixed so I have a new lever but first I need to remove the old bits.
I have removed the control lever panel.
The lever is held onto the shaft by a pin. This pin would need to be driven through but there isn't space behind. The lever would need to be pulled off the shaft but there doesn't look to be space between it and the gearbox. I am assuming that the casting that includes the handbrake and lowering control needs to come off. Before I start removing bits is there anything to watch out for.
I will need to disconnect the hydraulic linkage on the inside, do I need to secure anything first, it appears to be under tension.

Thanks for your advice.

Regards

Colin
Aberdeenshire

Re: Hydraulic Control Lever Broken

Posted: Sat Jul 06, 2019 12:24 pm
by cobbadog
Start spraying it with a product like WD40 to start the loosening process.

Re: Hydraulic Control Lever Broken

Posted: Sun Jul 07, 2019 8:30 am
by DB780
It would be easier working with the housing off especially if it is well seized. There are three bolts holding it on one tucked away on the outside that's not so easy to get at. You will need to remove the control rod, there is a collar behind the nut and another behind the arm, note the chamfer on the collars goes to the arm. When reassembling you will need a length of wire (I use a 1/16ins gas welding rod about 6ins long with a short right angle bend on one end), you will see a small hole in the control rod, push the spring and a collar along the rod passed the hole. Then insert the right angle bend into the hole, this will hold the spring and collar whilst you re-fit the housing. Once the housing is secured push the inner collar with a large screwdriver to compress the spring and the wire will come out the hole. Then fit the other collar and nyloc nut.

Re: Hydraulic Control Lever Broken

Posted: Sun Jul 07, 2019 11:32 am
by ollek
Some good and solid instructions given by DB780. After the nyloc nut is fitted, you will need to adjust it so to get the system working correctly. All Selectamatic adjustments can be found in the following link to a page on the David Brown Tractor Club. The page also gives some basic information's about the Selectamatic system, its function and fault finding http://dbtc.co.uk/index.php/information ... lic-system

Re: Hydraulic Control Lever Broken

Posted: Sat Jul 13, 2019 8:43 pm
by Colin6224#2
Hi
Thanks for the information. I finished reassembly today and it all went well.
Disassembly was helped by knowing there were three bolts to find. The hard to get at one isn't obvious. In my case the control lever was broken so I just too the control panel off which made it easier to get to. Same when I reassembled everything, I found that having the panel off made it possible.
Everything around that area is coated in oily dirt being so close to the hydraulic dump valve and camels hump so it all came apart pretty well. Once I had the casting off and on the bench, I punched the control lever pin out and used a bearing puller to remove the broken spindle from the shaft.
The new control handle is a lot stronger than the original, and pretty good quality but I did have to adjust the bend of the handle in the vice and drill out a couple of holes.
I used the bent wire trick to secure the spring but on the first attempt I couldn't get the wire out, so I had to pull everything out again and refit the wire so that it only just entered the hole in the shaft. That kept the spring in place until everything was reassembled but the wire could still be levered out.
One additional hint I would add for anyone doing this job, source a bolt of the same thread size, but longer than the one used to hold the casting in place. Having a longer bolt means you can see the bolt and align it with the threaded hole to align everything. Otherwise you have to try and align everything by touch which didn't work for me. Once the other two bolts are fitted loosely, you can swap out the long one.

One final comment.
As I had that casting off, I also took the opportunity to replace the brake pawl that holds the handbrake in tension. Easier to do on the bench.
I got the worn pawl out by removing the grease nipple and applying an airline to the hold. Popped out a treat.
The new pawl slid into the hole quite easily simply by using my finger and a screwdriver to guide it.

Thanks for your help Guys.

Colin

Re: Hydraulic Control Lever Broken

Posted: Sun Jul 14, 2019 10:00 am
by DB780
Hi Colin, It's good you got the job done and the long bolt is a good tip. You mentioned not being able to lever the wire out, you don't lever the wire out when the spring is compressed by pushing on the inner collar it should drop out. But not to worry all is well now.