1996 Toyota Previa AC cycles on and off

TECHBILL7

MEMBER
1996 TOYOTA PREVIA
4 CYL
2WD
AUTOMATIC
107,000 MILES

The ac clutch cycles on for about 2 sec and off for 20 sec. I put a low pressure gauge on the low side and it drops from 100 to 50 and then cycles off.
I tried to add refrigerant and only took a quater of a can and the problem is still the same.
I can see the drier in front of the condenser but I coulnt see if it has a sight glass.
The clutch does sound a little noisy for 2 sec its on.I don't know if its typical or not. I have gauges but I didnt check the high side at the same time.
I just bought this van with the problem.
I have a basic knowledge of ac and have replaced compressors and driers, flush and vac some of my previous cars. But know nothing of this system
Thanks in Advance
Bill

3 Replies

BMRFIXIT

MECHANIC
19,053 POSTS

The low side reading is very high
I would for sure check the high side too
suspect over charged system and or restriction
if that is for sure the low side reading

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Monday, December 29th, 2008 AT 6:55 PM

TECHBILL7

MEMBER
2 POSTS

BMRFIXIT Thanks for your responce.I let some refrigerant out and the compressor clutch stays on now. I must of let too much out because the low side is reading a zero and the high side is reading 125 psi. I noticed the high side going to the evaporator is very hot and the low side just warm. It seems like you were right on both counts 1 too much refrigerant and 2 maybe some sort of blockage.
Should I add some refrigerant to system to bring readings up. Do you think it could be a blocked expansion valve or the evaporator?