×
May 29-30th 2020 event at Rosedale Tech has been moved to April 30–May 1, 2021 (29 Apr 2020)

Full refunds will be given unless you want us to hold your spot for next year. Hope to see you there!
www.rosedaletech.org/diagnostics-seminar...aGdvxG1mVYe2wjxQ0mYw

× Help us help you. By posting the year, make, model and engine near the beginning of your help request, followed by the symptoms (no start, high idle, misfire etc.) Along with any prevalent Diagnostic Trouble Codes, aka DTCs, other forum members will be able to help you get to a solution more quickly and easily!

A/C Leak 92 BMW 535i

  • gary t
  • Topic Author
  • Offline
  • New Member
  • New Member
More
23 May 2020 13:28 #40132 by gary t
A/C Leak 92 BMW 535i was created by gary t
92 BMW 535i 3.5L; Seiko Seiki ss-148pb5 compressor; system completely empty within 24 hr.s AND 15-20 minute A/C functional drive. no bubbles after partial (3 of 4 cans) r-134 fillup. get a very weak, intermittent response from tif type leak detector around compressor pulley. couldn't find an evap drainage tube but ran leak detector near every undercarriage orifice I could find and got no response. left gauges connected overnite and surprise-surprise gauge pressures showing ambient garage temperature. Should I condemn front shaft seal, compressor or look for something else???

Please Log in or Create an account to join the conversation.

  • Hardtopdr2
  • Away
  • Junior Member
  • Junior Member
More
23 May 2020 21:04 #40137 by Hardtopdr2
Replied by Hardtopdr2 on topic A/C Leak 92 BMW 535i
Get a spraybottle and fill with soapy water (dawn dish soap). Pressurize system with air or nitrogen and spray all connecting points and charge ports as well as condenser. That fast of a leak should show up pretty quick

Please Log in or Create an account to join the conversation.

  • gary t
  • Topic Author
  • Offline
  • New Member
  • New Member
More
24 May 2020 10:00 #40148 by gary t
Replied by gary t on topic A/C Leak 92 BMW 535i
Sorry, I conflated 2 thoughts into 1 bad sentence: To be clear- I found no bubbles after filling system with air and sprayed all connections with soapy water. Then I evacuated and filled the system with 3 cans (system capacity is 56oz.) of r-134 and got a very mild, intermittent response from compressor front seal area with electronic detector. The car has now sat for 36 hours and the pressure gauges still match ambient temperature. Since the system only seems to go empty after considerable running time, I'm thinking the only component that can exhibit that kind of intermittent leak is the compressor front seal. What do you guys think??

Please Log in or Create an account to join the conversation.

  • Hardtopdr2
  • Away
  • Junior Member
  • Junior Member
More
24 May 2020 13:15 #40152 by Hardtopdr2
Replied by Hardtopdr2 on topic A/C Leak 92 BMW 535i
That is a possibility same as the air compressor seals if its a split case design. If you have a UV leak test kit it will show up. Did you spray all of the condenser or just fittings?

Please Log in or Create an account to join the conversation.

More
24 May 2020 23:02 #40175 by John Clark
Replied by John Clark on topic A/C Leak 92 BMW 535i
If you can't find the condenser drain, did you try putting your leak detector in the center air vents? Sometimes that will indicate when you have an evaporator leak.

Also, have you checked your service port valves? A leak that doesn't show with gauges can often be a bad shraeder valve.

Please Log in or Create an account to join the conversation.

  • Hardtopdr2
  • Away
  • Junior Member
  • Junior Member
More
25 May 2020 15:29 #40190 by Hardtopdr2
Replied by Hardtopdr2 on topic A/C Leak 92 BMW 535i
Here is a pressure temperature chart for reference
Attachments:

Please Log in or Create an account to join the conversation.

More
25 May 2020 15:39 #40191 by John Clark
Replied by John Clark on topic A/C Leak 92 BMW 535i
If he's looking for a leak, what's he going to do with a pressure/temp chart?

I have seen compressor case leaks that passed a vacuum leak test but would leak under pressure. The compressor shaft seal can do the same thing and leak worse when spinning. The other common place for leaks that seem to happen more when running is the condenser.

Please Log in or Create an account to join the conversation.

  • Hardtopdr2
  • Away
  • Junior Member
  • Junior Member
More
25 May 2020 15:57 #40192 by Hardtopdr2
Replied by Hardtopdr2 on topic A/C Leak 92 BMW 535i
He was mentioning that after it sat for 36 hours that pressures matched ambient temp and with it being static pressure that is about right. Though my fat thumb clicked wrong image lol here is the right one for static pressure
Attachments:

Please Log in or Create an account to join the conversation.

More
25 May 2020 16:44 - 25 May 2020 16:45 #40198 by John Clark
Replied by John Clark on topic A/C Leak 92 BMW 535i
Those charts are a rough guess, at best. During charging, I've seen the proper static pressures in the system with as little as 1/4-1/3 of the requisite charge. When you add the rest it doesn't change the static pressure very much. So, you can be as much as 1/2-3/4 low on charge and the static pressure will look normal. It just tells you there's enough for the compressor to turn on, at least for a brief time.

I think he's just comparing that to a day of driving it where all the refrigerant leaked out in a day.
Last edit: 25 May 2020 16:45 by John Clark.

Please Log in or Create an account to join the conversation.

  • Not Allowed: to create new topic.
  • Not Allowed: to reply.
  • Not Allowed: to add attachements.
  • Not Allowed: to edit your message.
Time to create page: 0.296 seconds