new hst install

I had a question related to the first use of a newly installed hst. I have almost completed the install of a replacement hst and will fill the hydro reservior with new super udt2. Do I need to do anything to prime the charge pump or do I just start it up and let it work out the air at idle? Seeing that the hst cost a good bundle I don't want to screw it up.

Thanks

Matt

PS this is the follow up to my fairly long thread about my hst failure on my bx1830

MattJ said:

I had a question related to the first use of a newly installed hst. I have almost completed the install of a replacement hst and will fill the hydro reservior with new super udt2. Do I need to do anything to prime the charge pump or do I just start it up and let it work out the air at idle? Seeing that the hst cost a good bundle I don't want to screw it up.

Thanks

Matt

PS this is the follow up to my fairly long thread about my hst failure on my bx1830

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You da man Matt; I'll be following this like a hawk!!!:thumbsup:

My BX 1500 is in the shop now for hydrostat probs. Dealer stopped by and said it seemed like the relief valves were stuck open. I hope it is that simple.

I think you just let it sit and run at medium speed to work the air out, that is what my book said.

Matt, how'd the install go, fix the problem??

I just finished buttoning up everything this morning. I had been traveling and also sick so its taken longer than it should. I will put in the fluids and try it out today or tomorrow.

So far my advice for the work is first, if you don't have an engine hoist for removing the tranmission and gearbox assembly per the manual just leave the wheels on and shift the tranny in neutral and carefully wheel it out of the frame. The second is that you really need a helper when reversing the process and putting the tranny/gearbox/axel back in. It's just too cumbersome to do it safely solo.

I also have the charge pressure gauge all built in so when its all working I'll take some pictures and post them.

So I put fluid in it and started it up. It ran for a few minutes without the charge pressure coming up and so I stopped it and checked the fluid level per the manual. It was now below the dipstick but I need to run to the dealer to get more super UDT2 as I was out. I'll fill it up again tomorrow and give it another whirl.

Does anybody know if you need to do anything to prime the HST other than just let it idle to work the air out? I did check the check valve on the bottom of the HST and it had oil in it, it just hasn't built a charge yet.

Thanks

Matt

I went through the shop manual for the BX1500 and the only thing I noticed that may be of interest here is that the HST uses Fluid from the Power Steering circuit to charge the HST.

So I was getting nervous running the tractor w/out charge pressure coming up per the new gauge I installed. So I bit the bullet and took it to the dealer and without even moving the tractor they figured it out. In my parts box from the old HST was a sealing collar I forgot to install. So this weekend I'll be taking it down the third time and installing the collar.

The first HST removal and install took about 11 hrs total. The second was under five with my neighbor helping. He's bringing over some of his better tools and we'll see how #3 goes. If anyone has HST replacement / tractor disassembly questions I'm becoming an expert.

I do have to say the local dealer was awesome in his patience with my questions.

At least the dealer is helpfull. Most dealings I have with the local dealers are not very helpfull.

So saw the best sight today, my tractor running, showing proper charge pressure, and driving like its new with full power. Yes, after three attempts I installed an HST correct. My advice if anyone follows is take pictures and bag everything in labeled bags. The work shop manual is OK but lacks the detail you need to ensure everything is 100% clear.

I also have my gauge installed, and it monitors charge pressure. Off the top of my head the range per the WSM is 42-70 psi. If I see the gauge drop the HST isn't getting hydraulic oil. I'm 99% certain this gauge would have saved me $1500 in parts and a lot of downtime.

For those who are interested here's the parts you need:

Oil Gauge Kit - can get from autozone or amazon (mine) Amazon.com: Auto Meter 2360 Auto Gage 2-1/16" 0-100 PSI Mechanical Individual Panel Oil Pressure Gauge: Automotive

1/8" to M14 adapter (goes into test port next to HST filter) - amazon Amazon.com: Auto Meter 2267 1/8" NPT to M14 x 1.5 Oil Pressure Metric Adapter: Automotive

a 1/8" male to 1/8" female elbow - from home depot, makes it so the line doesn't go straight down out of the test port. The elbow makes it much less likely to snag.

corregated wire wrap from autozone to help protect the 1/8" line from the port to the gauge

2" or 2 1/16" gauge pod from autozone or amazon. Can sand to fit the gauge into the opening.

To install I put the M14 adapter in, added the elbow, and ran the included 1/8" line under the chassis with the wiring harness. I came in through the battery area and mounted the gauge in the pod between the dash and FEL controls as it seemed like a protected spot. I split the backlighting line for the gauge off the headlight switch (if you want backlighting for night). The pod was shaped for a pillar on a car but I just reshaped it with a heatgun, very easy.

The total for all parts was about $50.

Happy trails

Matt