A/C Noise In Big Blue
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Re: A/C Noise In Big Blue
 
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Re: A/C Noise In Big Blue
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Re: A/C Noise In Big Blue
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In reply to this post by 85lebaront2
Time to close out this thread - SUCCESS!
Janey and I took Big Blue on a 150 mile jaunt yesterday and the A/C noise was just as obnoxious at the end as at the start. And it was really OBNOXIOUS. But I noticed that on bumps the sound changed a bit, almost sounding like the A/C compressor was loose. So today I started looking the A/C system over to see if anything was loose and I spotted something suspicious. In the pic on the left you can see that the aluminum can, which I think may be a filter but I can't find in any illustration of the A/C system, is touching the brake master cylinder. In the pic on the right it has been isolated from the M/C by a very fancy item - 4 layers of bicycle inner tube rubber. And the noise is gone!  Apparently the filter was transmitting the sound of the A/C compressor through the M/C and booster and into the firewall, which explains why I couldn't figure out where it was coming from. Anyway, the problem has been solved and I'll come up with a more elegant solution to keep the two components from touching.  
Gary, AKA "Gary fellow": Profile
Dad's: '81 F150 Ranger XLT 4x4: Down for restomod: Full-roller "stroked 351M" w/Trick Flow heads & intake, EEC-V SEFI/E4OD/3.50 gears w/Kevlar clutches
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Re: A/C Noise In Big Blue
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In reply to this post by Gary Lewis
Glad you found it!
Especially glad that the MC haven't rubbed a hole in the AC canister.  Though I'd watched your videos I certainly couldn't tell that the sound was coming from the brake booster into the cab. Do you think there is enough room in the mounts to shift the line? Or is there another application that doesn't have that can in the same place?
Jim,
Lil'Red is a '87 F250 HD, 4.10's, 1356 4x4, Zf-5, 3G, PMGR, Saginaw PS, desmogged with a Holley 80508 and Performer intake. Too much other stuff to mention. |
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Yes, I'm very glad to have found it. It was driving me bananas as it was directly tied to the compressor's RPM, going away completely when the compressor shut off and coming back instantly when it came on. And in town it was LOUD. I'm sure it was just as loud at speed, but there is so much more noise that it wasn't as intrusive.
 Like you, I would never have guessed the sound was coming in via the brake master cylinder/booster combo. I really thought it was coming in via the vents, but if you listened to them you couldn't tell for sure. Obviously now that's not where it was coming from - it was the whole firewall! But I don't want to change out the lines as they were expensive and would require re-charging the system. So I'll see if I can bend something or reroute things to get that part away from the M/C. Maybe just tweaking the tube going into the condenser will do it?
Gary, AKA "Gary fellow": Profile
Dad's: '81 F150 Ranger XLT 4x4: Down for restomod: Full-roller "stroked 351M" w/Trick Flow heads & intake, EEC-V SEFI/E4OD/3.50 gears w/Kevlar clutches
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Maybe!
 I couldn't say, as this truck has never had AC or Hydro boost. I do know a thing or two about bending aluminum tube but never tried it in place and under pressure.
Jim,
Lil'Red is a '87 F250 HD, 4.10's, 1356 4x4, Zf-5, 3G, PMGR, Saginaw PS, desmogged with a Holley 80508 and Performer intake. Too much other stuff to mention. |
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In reply to this post by Gary Lewis
Gary, I can't really see why they are anywhere near your master cylinder. Here are some pictures of Darth's AC lines in that area:
 
Bill AKA "LOBO" Profile
"Getting old is inevitable, growing up is optional" Darth Vader 1986 F350 460 converted to MAF/SEFI, E4OD 12X3 1/2 rear brakes, traction loc 3:55 gear, 160 amp 3G alternator Wife's 2011 Flex Limited Daily Driver 2009 Flex Limited with factory tow package Project car 1986 Chrysler LeBaron convertible 2.2L Turbo II, modified A413 |
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Bill - Remember that I have a 1990 system, not the later system that you have. The original hoses, aka manifold set, that I got from Huck had that "muffler" in the same spot as the new hoses/manifold that I had to buy to replace the leaky one. And it has it in the same spot, right up against the M/C.
As I said, the 1995 FSM doesn't show anything in the hose line at that spot, nor does the 1985. So it must be something with the 1990 system that I have. I'll take some more pics, although it may not be until Monday as I'm not sure what the plans are for Father's Day. But there has to be a way to change things just enough to have clearance there. 
Gary, AKA "Gary fellow": Profile
Dad's: '81 F150 Ranger XLT 4x4: Down for restomod: Full-roller "stroked 351M" w/Trick Flow heads & intake, EEC-V SEFI/E4OD/3.50 gears w/Kevlar clutches
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That may be it then, here is the only underhood picture of "Big Ugly" the 1990 F250 parts donor.
Bill AKA "LOBO" Profile
"Getting old is inevitable, growing up is optional" Darth Vader 1986 F350 460 converted to MAF/SEFI, E4OD 12X3 1/2 rear brakes, traction loc 3:55 gear, 160 amp 3G alternator Wife's 2011 Flex Limited Daily Driver 2009 Flex Limited with factory tow package Project car 1986 Chrysler LeBaron convertible 2.2L Turbo II, modified A413 |
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I think I see something in your pic, but that is on the line going to/from the compressor. I think the one on Big Blue is on the line to/from the condenser. Will try to get better pics soonest.
Gary, AKA "Gary fellow": Profile
Dad's: '81 F150 Ranger XLT 4x4: Down for restomod: Full-roller "stroked 351M" w/Trick Flow heads & intake, EEC-V SEFI/E4OD/3.50 gears w/Kevlar clutches
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Ok, more pics. On the right is the line coming from the compressor, going into the side of the muffler, and then going towards the front. Note that it is sandwiched between the MAF sensor and the air inlet to the air cleaner box so it can't go up nor down.
On the left is the line coming from the muffler to the front and into the condenser. I'm guessing that the line coming out of the condenser is longer than the one that was originally in there, which pushed the muffler rearward and into the master cylinder. However, having had 4 layers of inner tube rubber between the muffler and the M/C for two days the muffler no longer is up against the M/C. I think the rubber line has shifted a bit. But since I promised the shop that did the work I'd show them what the problem is, I'm going to leave the rubber out until tomorrow and take it in then. I think by then it'll be touching again and they can both see and hear the problem. Then I'll put the rubber back in and the problem will go away. And when I get it home I can figure out how to make the separation permanent.  
Gary, AKA "Gary fellow": Profile
Dad's: '81 F150 Ranger XLT 4x4: Down for restomod: Full-roller "stroked 351M" w/Trick Flow heads & intake, EEC-V SEFI/E4OD/3.50 gears w/Kevlar clutches
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Thought I'd update this, maybe for the last time?
 I've played around with various routes for the hoses and tubing, and have come to realize that the muffler needs to nest between the MAF sensor and the master cylinder because the hose has to go between the MAF sensor's frame and the inlet air tube. But that it'll move a bit as the engine rocks on its mounts. That movement tends to move, and ultimately toss out, the inner tube rubber I was using for isolation. So I've come up with the "solution" shown below. That's 1/2" heavy foam weatherstripping glued to the master cylinder so it won't go away. And in the shot on the right, which was taken from the engine's point of view, you can see a piece of foam insulation that protects the tube and hose from the MAF's plastic frame. Also, you can see a piece of inner tube that is glued in place between the MAF's frame and the end of the muffler. So the muffler can move w/o losing the isolation pieces, but I think most of the movement will be taken up by the bends in the hose you can see running to the compressor in the left pic. We shall see...  
Gary, AKA "Gary fellow": Profile
Dad's: '81 F150 Ranger XLT 4x4: Down for restomod: Full-roller "stroked 351M" w/Trick Flow heads & intake, EEC-V SEFI/E4OD/3.50 gears w/Kevlar clutches
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This post was updated on .
In reply to this post by Gary Lewis
That was actually "Big Ugly" the 1990 F250 parts donor. What you see is the upper hose to the compressor (suction) and possibly the discharge line. Notice no MAF.
Here is Darth's current system: 
Bill AKA "LOBO" Profile
"Getting old is inevitable, growing up is optional" Darth Vader 1986 F350 460 converted to MAF/SEFI, E4OD 12X3 1/2 rear brakes, traction loc 3:55 gear, 160 amp 3G alternator Wife's 2011 Flex Limited Daily Driver 2009 Flex Limited with factory tow package Project car 1986 Chrysler LeBaron convertible 2.2L Turbo II, modified A413 |
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