Doug, The heater may not be off and not warm just because you have turned to off the heater control, screwed in the mechanical heater valve or shut off the heater on some level. A liquid test is where you make sure the heater is not getting warm water by: -1-Feeling the cabin heater hoses which should be cabin temp. If warm then do to #2. If ok then heater is off unless high rpm = w/p velocities leak past the valve. -2-Using large radiator hose pinchers to pinch them closed, if warm, to see if a/c gets colder. If so the # 3. -3-If diff is noted then inspect valve cable closure device to see if fully closed. -4-If so closed and 1, 2 and 3 were followed, then remove valve and test its closure ability against pressured air or garden hose water for leak test. -5-Or just say the hell with all of the above and just install another heater valve out of view so you can totally shut off the hot water and be cool. Jeff Cobb Cell 225-907-4514 On Aug 6, 2016, at 11:59 AM, Doug <doug351c@gmail.com> wrote:
Jeff,
What do you mean by a heater "liquid test"?
Doug Braun Blue73L #5505
-----Original Message----- From: DeTomaso [mailto:detomaso-bounces@server.detomasolist.com] On Behalf Of JEFFREY COBB Sent: Friday, August 05, 2016 3:37 AM To: Pantdino <pantdino@aol.com>; detomaso@detomasolist.com Subject: Re: [DeTomaso] use sight glass in AC that has been retrofitted to 134a?
Jim, All cars use different pressures and for examples this week we did a/c work on a 124 Fiat, many Benz-Bmws-Toyotas, a 71 e-type, Ford +Chevy trucks, a Cobra kit car and a Mangusta. But basic pressures at 1,500 rpm with cooling fans on and on high, with both windows open, rear and front hatch closed, high fan and not on recirc should be about 35 + - low side and 250 + - high. Seems like a 7:1 ratio works the best. Converted systems do need different numbers but never too much of a change. So your low range should vary from 20 to 38 psi and the high 210 to 260 psi as long as above written parameters are meet. The proper pressures will equate to the coolest temps. You have to note that and remember you are just setting the vent output for the coolest temp not some pre-considered ideal temp you hope for. About 30 % of all of our a/c fixes are fixing the stuck on heaters. We are in hot Louisiana, make sure your heater is truly shut off by doing a liquid test. Do use the correct oil and add 2 oz if you are not sure of how much is in. You can always expel the working high side into a cloth or jug for 2 seconds to get an idea if you are oily enough. A lot of spit indicates fine but dry expelled gas needs oil. Keep cool,
Jeff
Jeff Cobb- I pad W-225-343-7525 C-225-907-4514 Jeff Cobb Auto Works 1316 S. Acadian Thruway Baton Rouge, La. 70806 www.LiveOakConcours.org
On Aug 4, 2016, at 11:05 PM, Pantdino <pantdino@aol.com> wrote:
Hi, Jeff,
What should the pressures be?
Thank you,
Jim
-----Original Message----- From: Jeff Cobb <jeffcobb1@me.com> To: Pantdino <pantdino@aol.com>; detomaso <detomaso@detomasolist.com> Cc: Jeff Cobb <jeffcobb1@me.com> Sent: Thu, Aug 4, 2016 6:55 pm Subject: Re: [DeTomaso] use sight glass in AC that has been retrofitted to 134a?
The sight glass is always used as a reference point. You must go by the dual gauges. Never by the low side only.
Jeff Cobb
On Aug 4, 2016, at 8:44 PM, Pantdino via DeTomaso <detomaso@server.detomasolist.com> wrote:
After switching the AC system to 134a, do you use the sight glass in the dryer or go by the pressure at the low pressure port like with modern cars?
Sorry, but I don't recall what I learned several years ago when I switched the system over.
Jim Oddie _______________________________________________
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Doug, The heater may not be off and not warm just because you have turned to off the heater control, screwed in the mechanical heater valve or shut off the heater on some level. A liquid test is where you make sure the heater is not getting warm water by: -1-Feeling the cabin heater hoses which should be cabin temp. If warm then do to #2. If ok then heater is off unless high rpm = w/p velocities leak past the valve. -2-Using large radiator hose pinchers to pinch them closed, if warm, to see if a/c gets colder. If so the # 3. -3-If diff is noted then inspect valve cable closure device to see if fully closed. -4-If so closed and 1, 2 and 3 were followed, then remove valve and test its closure ability against pressured air or garden hose water for leak test. -5-Or just say the hell with all of the above and just install another heater valve out of view so you can totally shut off the hot water and be cool. Jeff Cobb Cell 225-907-4514 On Aug 6, 2016, at 11:59 AM, Doug <[1]doug351c@gmail.com> wrote: Jeff, What do you mean by a heater "liquid test"? Doug Braun Blue73L #5505 -----Original Message----- From: DeTomaso [[2]mailto:detomaso-bounces@server.detomasolist.com] On Behalf Of JEFFREY COBB Sent: Friday, August 05, 2016 3:37 AM To: Pantdino <[3]pantdino@aol.com>; [4]detomaso@detomasolist.com Subject: Re: [DeTomaso] use sight glass in AC that has been retrofitted to 134a? Jim, All cars use different pressures and for examples this week we did a/c work on a 124 Fiat, many Benz-Bmws-Toyotas, a 71 e-type, Ford +Chevy trucks, a Cobra kit car and a Mangusta. But basic pressures at 1,500 rpm with cooling fans on and on high, with both windows open, rear and front hatch closed, high fan and not on recirc should be about 35 + - low side and 250 + - high. Seems like a 7:1 ratio works the best. Converted systems do need different numbers but never too much of a change. So your low range should vary from 20 to 38 psi and the high 210 to 260 psi as long as above written parameters are meet. The proper pressures will equate to the coolest temps. You have to note that and remember you are just setting the vent output for the coolest temp not some pre-considered ideal temp you hope for. About 30 % of all of our a/c fixes are fixing the stuck on heaters. We are in hot Louisiana, make sure your heater is truly shut off by doing a liquid test. Do use the correct oil and add 2 oz if you are not sure of how much is in. You can always expel the working high side into a cloth or jug for 2 seconds to get an idea if you are oily enough. A lot of spit indicates fine but dry expelled gas needs oil. Keep cool, Jeff Jeff Cobb- I pad W-225-343-7525 C-225-907-4514 Jeff Cobb Auto Works 1316 S. Acadian Thruway Baton Rouge, La. 70806 [5]www.LiveOakConcours.org On Aug 4, 2016, at 11:05 PM, Pantdino <pantdino@aol.com> wrote: Hi, Jeff, What should the pressures be? Thank you, Jim -----Original Message----- From: Jeff Cobb <jeffcobb1@me.com> To: Pantdino <pantdino@aol.com>; detomaso <detomaso@detomasolist.com> Cc: Jeff Cobb <jeffcobb1@me.com> Sent: Thu, Aug 4, 2016 6:55 pm Subject: Re: [DeTomaso] use sight glass in AC that has been retrofitted to 134a? The sight glass is always used as a reference point. You must go by the dual gauges. Never by the low side only. Jeff Cobb On Aug 4, 2016, at 8:44 PM, Pantdino via DeTomaso <detomaso@server.detomasolist.com> wrote: After switching the AC system to 134a, do you use the sight glass in the dryer or go by the pressure at the low pressure port like with modern cars? Sorry, but I don't recall what I learned several years ago when I switched the system over. Jim Oddie _______________________________________________ Detomaso Email List is not managed by POCA Posted emails must not exceed 1.5 Megabytes DeTomaso mailing list DeTomaso@server.detomasolist.com http://server.detomasolist.com/mailman/listinfo/detomaso To manage your subscription (change email address, unsubscribe, etc.) use the links above. Members who post to this list grant license to the list to forward any message posted here to all past, current, or future members of the list. They also grant the list owner permission to maintain an archive or approve the archiving of list messages. References 1. mailto:doug351c@gmail.com 2. mailto:detomaso-bounces@server.detomasolist.com 3. mailto:pantdino@aol.com 4. mailto:detomaso@detomasolist.com 5. http://www.LiveOakConcours.org/