Anyone replaced/simplified Selectamatic hydraulics?

The place to discuss all matters relating to David Brown Tractors. You will need to register your user name before you can post. If you have already registered could you please make sure that your location details have been completed. Go to My Account in the Main Menu on the left, and then go into "Edit Your Information" and complete your location details. Give the Country (and State/Province if you wish) if outside the U.K. County if within the U.K. Location details helps other members if you need spares, technical advice, or the nearest practical help.

DISCLAIMER -

David Brown Tractor Club Ltd
Forum/website Disclaimer

1. This [forum/website/chat room] and the advice and opinions expressed herein is not a solution for mechanical, electrical, valuations, other problems, breakdowns or issues experienced in relation to the vehicles referenced.

2. If reliance is thought to be placed on any of the information guidance or input provided such information will be expressly confirmed as appropriate to be relied upon.

3. In the absence of any such confirmation no reliance should be suggested or inferred.

4. Members must not disclose information to 3rd parties in anticipation that reliance will be given by non-members.

5. Non-members must not purport to give advice on behalf of David Brown Tractor Club.

6. If you or someone you know is experiencing difficulties or repeated breakdowns you must seek assistance for an appropriately qualified expert who holds themselves out as such.

7. Any comments are free of charge and made or posted on an ex gratia basis. No member or non-member may advertise their professional services

Any user inactive for more than 3 months will automatically be deactivated, please contact admin@dbtc.co.uk if you would like to be reactivated.

Please be aware that your user name and entered location can be seen by all members. We only store information you have entered which is your email address and username, your IP is also stored, we have no access to private passwords.

If you do not agree with your information being stored, please do not register an account, If you wish to unsubscribe at any time please email admin@dbtc.co.uk giving your username.

Amended 27/10/18

Moderators: Segrie61, admin

User avatar
ollek
Posts: 3566
Joined: Tue Apr 10, 2012 1:20 pm
Location: South West Finland

Re: Anyone replaced/simplified Selectamatic hydraulics?

Post by ollek » Sat Jun 30, 2018 5:09 am

Swapping the Cessna spool valve for a camels hump will not rule out any internal leaks. What is the pressure measured at one of the quick couplers connected to the Cessna valve? A low pressure shows that the pump is bad, the pressure relief valve is bad or the pipe between the pump and the Cessna valve is bad or the O-ring at the pump end is damaged. The Cessna valve is not the culprit if the pressure is low and I have said this several times before. On the other hand, if you want to find this out the hard way, please do so.

cossyrec
Posts: 56
Joined: Mon Apr 17, 2017 9:04 pm
Location: East Yorks

Re: Anyone replaced/simplified Selectamatic hydraulics?

Post by cossyrec » Sun Jul 01, 2018 12:38 am

so if you have full pressure to Cessna valve it is impossible for it to leak via o rings on spool to leak back to return and onwards to transmission lubrication pipe ? eg fault in Cessna valve or as you are suggesting Cessna valve is bullet proof and cannot go wrong

User avatar
ollek
Posts: 3566
Joined: Tue Apr 10, 2012 1:20 pm
Location: South West Finland

Re: Anyone replaced/simplified Selectamatic hydraulics?

Post by ollek » Sun Jul 01, 2018 5:10 am

The Cessna valve construction does not make it possible for it to leak internally to the extant that the pressure from it is drastically reduced. There is no O-rings on the spool to seal the pressure ports. The two O-rings on the spool are there only to stop any small leak to the outside of the valve. A big enough internal leak to reduce the pressure out from the valve must be because of a drastically worn spool, and I haver been working with Cessna valves (and other spool valves) for more then 40 years and have never seen this happen. A drastically worn spool will show up as a massive leak to the outside from one or both ends of the spool. Please be informed that all spool valves have a small internal leak, but this does not effect the pressure you get from the valve. I have not been talking about the pressure TO the Cessna valve, but about the pressure FROM the Cessna valve (quick couplers). I ask again, what pressure can you obtain from the Cessna valve? Please connect a pressure gauge to one of the quick couplers connected to the Cessna valve and measure the maximum pressure. If the pressured is low, please see my previous postings, telling you about possible reasons for the low pressure.

cossyrec
Posts: 56
Joined: Mon Apr 17, 2017 9:04 pm
Location: East Yorks

Re: Anyone replaced/simplified Selectamatic hydraulics?

Post by cossyrec » Sun Jul 01, 2018 3:55 pm

if you read post it says 400 psi on one port less on the other I know this is low I would have thought if pump or main relief would have been same on both ports
Last edited by cossyrec on Thu Jul 05, 2018 10:13 am, edited 1 time in total.

880Aubrey
Posts: 23
Joined: Fri Jul 28, 2017 4:13 pm
Location: USA

Re: Anyone replaced/simplified Selectamatic hydraulics?

Post by 880Aubrey » Mon Jul 02, 2018 6:59 pm

Correct,one connection from the Cessna valve will reach 400PSI at full motor RPM.

I will Check the Pump, valve and connecting tubing.

Olek, My only real reason for replacing the cessna valve was to replace with a modern, serviceable multi spool valve.I understand now that the existing cessna could be expanded to an additional service and I will keep this in mind.

Cossyrec, please continue to forward your sketch when its available. I am still interested in possibly configuring the hydraulics as you have them.

It will be a few weeks before I get into the pump housing. I will update everyone with my findings/questions.

cossyrec
Posts: 56
Joined: Mon Apr 17, 2017 9:04 pm
Location: East Yorks

Re: Anyone replaced/simplified Selectamatic hydraulics?

Post by cossyrec » Thu Jul 05, 2018 10:20 am

db bodge plate.JPG
db bodge plate.JPG (66.97 KiB) Viewed 860 times

cossyrec
Posts: 56
Joined: Mon Apr 17, 2017 9:04 pm
Location: East Yorks

Re: Anyone replaced/simplified Selectamatic hydraulics?

Post by cossyrec » Thu Jul 05, 2018 11:04 am

basically three bushes bored same dia as holes in Cessna valve other end tapped 3/8 bsp or a union welded on assemble plate on to tractor then push bushes over pipes hold square and tack weld in to plate. welds not critical as pipes seal in side bushes not on mounting face. when every thing has been tested the gap around the bottom of plate could be sealed with silicon sealer or a large thick gasket it is only to stop ingress of muck not hold pressure. the rear most pipe is blanked of the centre pipe is pressure from pump to start with connect pressure gauge to this. if pressure is low start back tracking to find cause eg pump relief valve. pipe also becomes feed for spool valves. pipe nearest front becomes return to tractor from spools. the whole thing can be removed and tractor restored to standard at any time Fear my sketch and description may not be to clear but once Cessna vale is removed it should become self explanatory

User avatar
ollek
Posts: 3566
Joined: Tue Apr 10, 2012 1:20 pm
Location: South West Finland

Re: Anyone replaced/simplified Selectamatic hydraulics?

Post by ollek » Thu Jul 05, 2018 2:57 pm

I have said, and I say it again. I can not see any reason for modifying a tractor that have a Cessna valve in order to active what the OP has asked for. I have been given all instructions needed in order to use the Cessna valve on its own or as a supply unite to multiple external spool valves. Removing the Cessna valve and the bottom slice and fitting a serial connection block as shown in the drawing, is only costly, involves a lot of useless work and will not be of any benefit compered to the Cessna valve. The block as shown in the drawing is for use in tractors that have the camels hump only and not for tractors with a Cessna valve. Please leave the Cessna valve in place and fix the low pressure issue.

cossyrec
Posts: 56
Joined: Mon Apr 17, 2017 9:04 pm
Location: East Yorks

Re: Anyone replaced/simplified Selectamatic hydraulics?

Post by cossyrec » Fri Jul 06, 2018 12:11 am

to be fair removing the Cessna valve creates room to fit spool valves

cossyrec
Posts: 56
Joined: Mon Apr 17, 2017 9:04 pm
Location: East Yorks

Re: Anyone replaced/simplified Selectamatic hydraulics?

Post by cossyrec » Fri Jul 06, 2018 10:17 pm

alternatively you might be able something like this to suit the three pipe stubs https://hydraulicmegastore.com/product/ ... -coupling/

User avatar
ollek
Posts: 3566
Joined: Tue Apr 10, 2012 1:20 pm
Location: South West Finland

Re: Anyone replaced/simplified Selectamatic hydraulics?

Post by ollek » Sat Jul 07, 2018 5:11 am

Cossyrec, your in line connector is not needed, as the tractor has a Cessna valve. This type of in line connector is a step back if fitted to a tractor with a Cessna valve. And one more important thing about the in line connector. The plate (3/8") showed in your drawing must not get in contact with the pipe locating plate when the bolts are tighten down. Please have a look at the underside of a camels hump, there is a recess machined for the pipe locating plate. The inner diameter for the bushes must have the same diameter as the drillings in the Cessna valve base plate. The Cessna valve is not fitted on top of the pipes but on top of the base plate. Please see a page from the parts catalogue in the following link. https://partstore.caseih.com/us/parts-s ... 85ar317846

cossyrec
Posts: 56
Joined: Mon Apr 17, 2017 9:04 pm
Location: East Yorks

Re: Anyone replaced/simplified Selectamatic hydraulics?

Post by cossyrec » Sat Jul 07, 2018 6:12 pm

my wrong I forgot to suggest putting four washers/spacers under plate . but you will agree I had it in mind when I suggested sealing gap around plate with thick gasket or sealer to prevent ingress of muck I suggested the unions as a means of connection with out having to have any machining ability

User avatar
ollek
Posts: 3566
Joined: Tue Apr 10, 2012 1:20 pm
Location: South West Finland

Re: Anyone replaced/simplified Selectamatic hydraulics?

Post by ollek » Sat Jul 07, 2018 6:44 pm

The main point still remains. You do not have to manufacture anything like the part shown in the drawing, as the tractor has a Cessna valve. I can not help people that will not listen.

cossyrec
Posts: 56
Joined: Mon Apr 17, 2017 9:04 pm
Location: East Yorks

Re: Anyone replaced/simplified Selectamatic hydraulics?

Post by cossyrec » Fri Aug 17, 2018 11:27 pm

guess its up to 880aubrey which way he goes. For myself I wanted a useable piece of kit that would work for quite a number of years with out a big expense but have saved all the parts so if any future custodian wants to restore to original has the option

Post Reply

Who is online

Users browsing this forum: Google [Bot] and 24 guests