JD70 LP question

JPFL · Regular Joined: 01 Dec 2012 Posts: 41 Report to Moderator

New to me 70LP, have not gotten a service manual yet. Does the LP come in close contact with the cooling system? I am getting coolant from the round diaphram between the fuel valve and the manifold. Thanks in advance for any info. Jim

NEIADan · Posted: Thu Jan 10, 2013 7:17 pm Post subject: Re: JD70 LP question

It sounds like you are talking about the vaporizer. On the one side you have a diaghram that open and closes to match the vacuum of your intake. On the other side you have coolant circulating through a circular honeycomb and liquid propane in separate valley. The idea is to use the heat from the coolant to preheat the lp to a vapor in correlation with the diaghram of going from high pressure to a lower pressure in the intake providing the most vaporization of the lp. Those aluminum vaporizers are easily damaged allowing anti freeze to leak. often taking it apart and resurfacing the aluminum comb and plate with a new gasket and sealant it can be remedied.

JPFL · Regular Joined: 01 Dec 2012 Posts: 41 Report to Moderator

Thanks Dan, I will need to wait until manual comes. Jim

Hugh McKinney · Posted: Thu Jan 10, 2013 8:50 pm Post subject: Re: JD70 LP question

I have got a 70 LP and I recently had the exact same experience. It turned out that the aluminum passages through the Century vaporizer/regulator had developed pits where the gasket surfaces should not have any. By the way, no, there should not be any direct contact between the propane and the antifreeze/coolant. What I did, that fixed my problem is, I got about ten sheets of 120 grit sandpaper, and sanded both the body of the regulator/vaporizer and the cover (the one that doubles as a mounting plate to the bracket on the tractor) , until it they were really flat. I also used a little JB Weld to speed things up. I did it about 5 months ago, and after installing a new kit from Carb & Turbo Systems, it has performed flawlessly. Good luck, and be persistent, it's not rocket science, it just takes a lot of effort to sand it really flat and make it leak-proof. Hugh

Dan in North Houston · Posted: Fri Jan 11, 2013 4:40 am Post subject: Re: JD70 LP question

Which manual have you ordered? I have a 630LP and the deere service manual for the 630 (SM2008 for the 60 series) doesn't have much on the LP system.
There is a separate service manual for the LP gas tractors - SM-2015 "LP-Gas equipment for John Deere Tractors". It has the details that you are looking for.

STYLED DEERES · Posted: Sat Jan 12, 2013 2:44 am Post subject: Re: JD70 LP question

HUGH could I get the phone # for that place please I cant seem to get rebuild kits for the M-4 converters for my 620s &720s.I tried Nick BERBIERI and Davenport no luck.

Dalet · Posted: Sat Jan 12, 2013 7:12 am Post subject: Re: JD70 LP question

http://www.carbturbo.com/

JPFL · Regular Joined: 01 Dec 2012 Posts: 41 Report to Moderator

Dan, I got in touch with JD customer services and a young lady e-mailed me a manual on 70 JD LP-gas instructions (# OMR2050 D3) that helped a lot. It did not go into rebuilding the vaporizer, said to send to JD dealer for repair. So I am still looking, I tried to contact Century Gas Equipment in Lynwood CA. I will try again Mon to contact them. The vaporizer is a model "M". Thanks for the help. Jim --No-Advertising-in-Forums

JPFL · Regular Joined: 01 Dec 2012 Posts: 41 Report to Moderator

Styled Deeres, I had my vaporizer rebuilt by a local LP man and he replaced my M-4 with a M-5, he had a kit for my M4 but it was beyond repair.So he rebuilt a M5 for my tractor. Let me know if you still need a kit??? Jim --No-Advertising-in-Forums

Allis Chalmers	Case	Cockshutt	Farmall IH	Ford 8N,9N,2N	Ford
H. Ferguson	John Deere	Massey	Minn. Moline	Oliver	All The Rest