Dexta hydraulics not functioning

[Johnny Boy]

My first post, so hello everyone. I've been lurking for a while and found some really useful information.

I've had my '63 dexta for about 4 years and apart from the usual dexta gearbox issues it's been reliable.

Just recently the lift arms started getting a bit lazy when the tractor was first started, but after about half a minute they would lift and continue working for the rest of the day. Now they have stopped working i.e. fail to lift. You can lift the arms manually. I wanted to clean the filter so removed the top cover and hydraulic pump. Filter was a bit mucky but not to bad. Checked unloading valve and it moved freely. Top back on, almost 20 litres of SAE 30 and give it a try......no different. My tractor doesn't have a "tipping pipe" , but I removed the large bolt were it would attach and pulled out the external services button but no oil there. Does that mean my problem is with the pump?. Any advice what to try next is much appreciated.
When I get the dexta sorted I will have a look at the Super Major I bought last week. Runs really well, but lift arms don't work!.

Thanks

John

[Billy26F5]

Have you checked the unloading valve plug? Other than that it could also be a binding control valve. I doubt it'll be the pump but not impossible.
Here's the manual: http://www.smallholderservices.co.uk/si ... hydraulics
What year is the Super Major? (serial number if possible too) I suspect it has the same problem, the hydraulics are very similar, but not the same.
Sandy

[Johnny Boy]

Thanks Sandy,

Looks like it's top cover off again then.

Serial number of Super Major is 08D9 948713

Dexta is 1546889 series 908596

Both are in France so I think there are minor differences to UK market models, mainly no swinging drawbar as 50/60's tractors over here have the drawbar above the PTO, rather than below as in UK.
Regards

John

[Billy26F5]

The Super Major is an NP, late January 64, the serial number should actually read 08D-948713. Here's the manual for those hydraulics: http://www.fordson.se/6A_Hydraul_Suplem ... 01-024.pdf http://www.fordson.se/6B_Hydraul_Suplem ... 25-050.pdf
The Dexta appears to be a mid February 64, do you have the 09D- prefix in the serial number?
Apart from the drawbar I suspect the only other differences are the atomiser in the Dexta's intake manifold and the use of the earlier lights and pressings on the grills.
Sandy

[Johnny Boy]

Hey Sandy, you were absolutely correct, it was the unloading valve that had stuck. Gave it a polish and all ok now.

Do you think that is what I should be looking at on the Super Major?. Definitely won't be trying to manhandle that top cover, will get hold of a crane or similar. Thanks for the links to the SM manual.

Can't see a prefix on either the engine number on the block or the plate adjacent to the battery. It is a Dexta Special. As you say it has atomiser and headlights are not within radiator grills. It has live drive and diff lock, but maybe they all did towards the end of production?. Will post some pictures.

Thanks again for your help.

Regards

John

[Billy26F5]

The diff lock was fitted from November 61 (I presume from 09A-312001 but there's no mention of what serial number, which is unusual) on all tractors, The live clutch was always optional.
The usual plate on the firewall has no serial number, the engine number on the block has no prefix, only the serial number on the LH bell housing flange level with the timing inspection cover.
Very definitely expect it to be the same on the Super Major, ensure the top cover is perfectly square for the first 2" of lifting or the feed pipe bracket will crack.
Pics of both would be great.
Sandy

[Jerry Coles]

Re the top cover being square when lifting it off for the first 2".
Remove all the bolts and then before lifting fit at least two longer bolts or better still some studs so that the top cover is guided upwards. IMHO.
Cheers
Jerry

[Billy26F5]

Even doing that you still need to be careful, as there is room for misalignment there. What is really important is to get the lifting point just right, as then the cover will want to stay square without needing to actively hold it like that. Still better than not having any studs.
Sandy

[Johnny Boy]

Thanks guys.

Top cover on Major removed and unloading valve and control valve were seized. Both moving again freely now. Regarding the oil pipe, I'm not sure how far down into the casting it should sit, I'm assuming the collets should not be visible?. My pipe is springy (technical term) so as I press it down into the casting it's springs back up again, I've not yet tried pushing it down with collets fitted as maybe they will hold it down, but concerned about them disappearing never to be seen again.

Thanks

John

[Billy26F5]

The collets should have stayed in, but do make sure you don't loose them as otherwise the pipe will not stay in place. The pipe should be in a similar position to what you see on page 9 fig 11 of this: http://www.fordson.se/5_Bakaxel_Supleme ... 01-015.pdf
Sandy

[Johnny Boy]

Thanks again Sandy,

My pipe is definitely sitting higher than the illustration. I've covered everything up at the moment as I'm working outside and it's a bit showery.

As I pressed the pipe down earlier it was just springing back up. Will fully lift the top cover back out of the way and have another look, it's hovering about 20 CMS above the tractor at the moment.