Air bleeds on John Deere 750a

[Feldspar]

When our 750a was new we fitted air bleeds to the drill to try and prevent seed bouncing out the slots. We only had them on for a short time because some seed came out of the bleed hole rather than going down to the coulter. It was rather annoying because we had shortened the pipes to fit them which never fitted quite as well again. I remember having to duck tape the holes up for a few days before we had a wet day to remove them.

Since fitting the Pro Series seed boot to our drill we have had a lot of problems with blockages. We did not replace the firming wheel. @Simon Chiles is aware of one other person who did the same thing and also had a lot of problems with blockages. I think we will try and put the new style firming wheels on (a pain because they're quite expensive).

At first we thought the blockages were caused because of the wet conditions in the autumn with mud picking up on the firming wheels which then blocked the seed boot due to the different shape of them. However, we then had blockages in the spring when it was quite dry. Partly the thought was we were running the fan speed too high (4250 rpm) so we dropped down to about 3500 rpm, but that didn't seem to cure the issue. It always seems to be the front right section of a 6m drill that blocks (as you look from the tractor end); almost never coulters the back gang, which is weird.

As part of a multi pronged strategy to sort out this blockage problem I was considering putting the air bleeds back on again, but I didn't want them spitting seed all over the place again. Lots of other people seem to use them, so I don't know why we had a problem particularly. What can we have been doing wrong?

 

[Feldspar]

@parker @Louis Mc @Clive @AF Salers

 

[Clive]

We ran the weaving air bleeds both the 750a's we had, never had a issue with them spitting seed out (unless a coulter was blocked) I think they reduced coulter blockages as we could alway run fan higher without seed bounce

No experience of the pro series opener however

 

[AF Salers]

Same as you I was disappointed with the amount of seed spat out of the weaving air bleeds on my 750 so removed & sold them on.

Only done 50 acres with the pro series so far so no experience of blockages yet, though I did swap the firming wheels also as Simon advised of the blockage problem if not.

Re your front gang blockages. Is the drill level side to side & front to back?

 

[Feldspar]

Same as you I was disappointed with the amount of seed spat out of the weaving air bleeds on my 750 so removed & sold them on.

Only done 50 acres with the pro series so far so no experience of blockages yet, though I did swap the firming wheels also as Simon advised of the blockage problem if not.

Re your front gang blockages. Is the drill level side to side & front to back?

Interesting that you too had problems with the air bleeds.

On it being level, we do try and get it level by eye, but that is assuming it isn't that sensitive to being a little bit out. Maybe this is an incorrect assumption. Something needs to explain why it's the front right of the drill that seems the most prone.

 

[Feldspar]

The other option I wondered about was fitting blockage sensors. Has anyone done this and been pleased with the results?

 

[AF Salers]

Tape measure would be advisable, always amazes me how the eye can be deceptive

 

[KJM]

Is the coulter blocking with soil on the end? I don't think air bleeds would help if that's the case as the air flow in the coulter is about half after the air bleed. I was having problems at low fan speeds to try and reduce seed blowing out the slot causing the seed to settle out on flat areas of the pipe. Air bleeds allow me to run the fan faster. I usually run about 4200rpm on 6m. It was always a problem on the wings of the drill as that is where the flattest sections are.

I have blockage sensors on my other drill and it is very nice just to check at a glance. It is also very helpful when running low on seed to be sure you haven't run out. I have fitted a camera in the hopper of the 750A which helps. I wouldn't use air bleeds with a blockage sensor as when a coulter blocks it can come out the vent.

I am still on the 90 series boot but have fitted one of the new style firming wheels as an experiment, but sadly I can see no difference in the final result.

 

[Simon Chiles]

Is the coulter blocking with soil on the end? I don't think air bleeds would help if that's the case as the air flow in the coulter is about half after the air bleed. I was having problems at low fan speeds to try and reduce seed blowing out the slot causing the seed to settle out on flat areas of the pipe. Air bleeds allow me to run the fan faster. I usually run about 4200rpm on 6m. It was always a problem on the wings of the drill as that is where the flattest sections are.

I have blockage sensors on my other drill and it is very nice just to check at a glance. It is also very helpful when running low on seed to be sure you haven't run out. I have fitted a camera in the hopper of the 750A which helps. I wouldn't use air bleeds with a blockage sensor as when a coulter blocks it can come out the vent.

I am still on the 90 series boot but have fitted one of the new style firming wheels as an experiment, but sadly I can see no difference in the final result.

Unless you change the boot as well you won’t see a difference with the new pro series press wheel other than not ripping the tyre off the rim when you do sharp turns.

 

[Robt]

Hi James, we fit them as standard on our seed drills, we have had them as standard for a number of years. Call me tomorrow to see if I can help 07741643968

 

[Simon Chiles]

When our 750a was new we fitted air bleeds to the drill to try and prevent seed bouncing out the slots. We only had them on for a short time because some seed came out of the bleed hole rather than going down to the coulter. It was rather annoying because we had shortened the pipes to fit them which never fitted quite as well again. I remember having to duck tape the holes up for a few days before we had a wet day to remove them.

Since fitting the Pro Series seed boot to our drill we have had a lot of problems with blockages. We did not replace the firming wheel. @Simon Chiles is aware of one other person who did the same thing and also had a lot of problems with blockages. I think we will try and put the new style firming wheels on (a pain because they're quite expensive).

At first we thought the blockages were caused because of the wet conditions in the autumn with mud picking up on the firming wheels which then blocked the seed boot due to the different shape of them. However, we then had blockages in the spring when it was quite dry. Partly the thought was we were running the fan speed too high (4250 rpm) so we dropped down to about 3500 rpm, but that didn't seem to cure the issue. It always seems to be the front right section of a 6m drill that blocks (as you look from the tractor end); almost never coulters the back gang, which is weird.

As part of a multi pronged strategy to sort out this blockage problem I was considering putting the air bleeds back on again, but I didn't want them spitting seed all over the place again. Lots of other people seem to use them, so I don't know why we had a problem particularly. What can we have been doing wrong?

I only know of two drills that have problems with the pro series boot, you and one other. Everyone else has been very impressed, me included. It can’t be coincidence that both of you that have had the problems were also the two that didn’t change the press wheel at the same time. Needham also don’t rate the pro series boot however I think their problem is the same as yours ie they are trying to run it with their own press wheel. The pro series boot cannot be more prone to blocking on its own. Although it is narrower the internal dimensions are the same. I’ve drilled winter beans with a tgw of 709 at 400 kg/ ha and not had a problem.
As for the air diffusers I personally think that they are a waste of time, however I’d be the first to admit that I spend a lot of attention to detail with the fan speed. I can understand that the air diffuser would give you a bit of tolerance on your fan if you weren’t as likely to adjust it as much. @H.Jackson has run pro series boots and press wheels all this spring with air diffusers and a 6 m drill and hasn’t had a problem. He’d spend as much attention to the fan speed as I would.

 

[H.Jackson]

All I can add is I use difusers to slow seed speed and reduce bounce not to avoid altering the fan speed.

 

[Feldspar]

Is the coulter blocking with soil on the end? I don't think air bleeds would help if that's the case as the air flow in the coulter is about half after the air bleed. I was having problems at low fan speeds to try and reduce seed blowing out the slot causing the seed to settle out on flat areas of the pipe. Air bleeds allow me to run the fan faster. I usually run about 4200rpm on 6m. It was always a problem on the wings of the drill as that is where the flattest sections are.

I have blockage sensors on my other drill and it is very nice just to check at a glance. It is also very helpful when running low on seed to be sure you haven't run out. I have fitted a camera in the hopper of the 750A which helps. I wouldn't use air bleeds with a blockage sensor as when a coulter blocks it can come out the vent.

I am still on the 90 series boot but have fitted one of the new style firming wheels as an experiment, but sadly I can see no difference in the final result.

This is a picture of what was happening in the autumn. I thought mud was picking up on the wider firming wheel (not Pro Series design), which then rubbed against the disc and put mud on the disc. We only found mud on the bevel side of the disc, which is weird because this side should be in the shadow of the disc. Ended up removing the firming wheels to see if that would help, but then the weather really closed in and we did nothing more until the spring when we put them back on again.

I would have just said it was this, but as I mentioned above, we had the problem in the spring when conditions were dry on top and no mud was being picked up. You are right that the most blockage prone pipes either had a flat section in the tank or a flat section running out to the wing.

The only other think Simon mentioned was whether the priority flow was set to high on the lift/lower causing the fan speed to dip too much at the ends of runs. That I need to check for next time.

 

[Feldspar]

I only know of two drills that have problems with the pro series boot, you and one other. Everyone else has been very impressed, me included. It can’t be coincidence that both of you that have had the problems were also the two that didn’t change the press wheel at the same time. Needham also don’t rate the pro series boot however I think their problem is the same as yours ie they are trying to run it with their own press wheel. The pro series boot cannot be more prone to blocking on its own. Although it is narrower the internal dimensions are the same. I’ve drilled winter beans with a tgw of 709 at 400 kg/ ha and not had a problem.
As for the air diffusers I personally think that they are a waste of time, however I’d be the first to admit that I spend a lot of attention to detail with the fan speed. I can understand that the air diffuser would give you a bit of tolerance on your fan if you weren’t as likely to adjust it as much. @H.Jackson has run pro series boots and press wheels all this spring with air diffusers and a 6 m drill and hasn’t had a problem. He’d spend as much attention to the fan speed as I would.

I was trying to remember whether on the old style boots whether the angle in green is the same as the Pro Series ones? I just seem a bit of a problem that the angle is such that the leading edge of the boot doesn't scrape off enough mud, leaving a ring of mud that can enter the boot (red arrow) and block it.

 

[Feldspar]

Hi James, we fit them as standard on our seed drills, we have had them as standard for a number of years. Call me tomorrow to see if I can help 07741643968

Thanks, Rob. I wondered if I had them on the wrong way round!

 

[Simon Chiles]

I was trying to remember whether on the old style boots whether the angle in green is the same as the Pro Series ones? I just seem a bit of a problem that the angle is such that the leading edge of the boot doesn't scrape off enough mud, leaving a ring of mud that can enter the boot (red arrow) and block it.

View attachment 902031

The base of the boot should run parallel to the ground. It won’t if your frame is not level. Also if the frame isn’t level it will mean that the seed boots are at different angles to the soil between front and rear gangs, normally shown up as uneven seeding depth.

 

[Simon Chiles]

This is a picture of what was happening in the autumn. I thought mud was picking up on the wider firming wheel (not Pro Series design), which then rubbed against the disc and put mud on the disc. We only found mud on the bevel side of the disc, which is weird because this side should be in the shadow of the disc. Ended up removing the firming wheels to see if that would help, but then the weather really closed in and we did nothing more until the spring when we put them back on again.

I would have just said it was this, but as I mentioned above, we had the problem in the spring when conditions were dry on top and no mud was being picked up. You are right that the most blockage prone pipes either had a flat section in the tank or a flat section running out to the wing.

The only other think Simon mentioned was whether the priority flow was set to high on the lift/lower causing the fan speed to dip too much at the ends of runs. That I need to check for next time.

View attachment 902025

You shouldn’t be getting mud built up on the inside edge of the disc like this, obviously it doesn’t help if you are trying to seed into soil in a wet a condition. Soil on the press wheels like this is in these conditions is caused by trying to force the seed trench too wide, obviously it doesn’t help if the press wheel is wider than the boot but it’s also a symptom of too high press wheel pressure. Technically you shouldn’t be seeding when it’s like that but if you really must ( personally I wouldn’t ) then you need to either firstly reduce press wheel pressure, secondly try lifting the press wheels out of work with a cable tie or thirdly try removing them completely.

 

[Badshot]

The air bleeds on my gd are buggers for letting seed blow out.
Getting fan speed right is the only way to reduce it, and that's trial and error.

 

[parker]

When our 750a was new we fitted air bleeds to the drill to try and prevent seed bouncing out the slots. We only had them on for a short time because some seed came out of the bleed hole rather than going down to the coulter. It was rather annoying because we had shortened the pipes to fit them which never fitted quite as well again. I remember having to duck tape the holes up for a few days before we had a wet day to remove them.

Since fitting the Pro Series seed boot to our drill we have had a lot of problems with blockages. We did not replace the firming wheel. @Simon Chiles is aware of one other person who did the same thing and also had a lot of problems with blockages. I think we will try and put the new style firming wheels on (a pain because they're quite expensive).

At first we thought the blockages were caused because of the wet conditions in the autumn with mud picking up on the firming wheels which then blocked the seed boot due to the different shape of them. However, we then had blockages in the spring when it was quite dry. Partly the thought was we were running the fan speed too high (4250 rpm) so we dropped down to about 3500 rpm, but that didn't seem to cure the issue. It always seems to be the front right section of a 6m drill that blocks (as you look from the tractor end); almost never coulters the back gang, which is weird.

As part of a multi pronged strategy to sort out this blockage problem I was considering putting the air bleeds back on again, but I didn't want them spitting seed all over the place again. Lots of other people seem to use them, so I don't know why we had a problem particularly. What can we have been doing wrong?

 

[parker]

I have never fitted air bleeds as I have never had the need.
pro series boots have only impressed me so far and have made a big difference to the drill with no blockage problems, I did change the press wheels on the advice of @Simon Chiles