jbeary Posted October 15, 2013 Share Posted October 15, 2013 (edited) Hi All,Wire loom replacement project wrapping on my 1991 Reatta. I found a loose hose and I don't know what to do with it. Please see attached pics. This is a rubber 1/4 vacuum hose that's attached to a poly line that runs with & to transmission wire harness. I think it terminates at the passenger side firewall but I could be wrong. Can't find any mention of it in the FSM and it's not on the EGR diagram. Nothing seems to be out of sorts with the cruise or heater programmer or any of the other vacuum actuators so I thought this may go to the transmission but can't find where. Any help would be appreciated. BTW: this same hose does not exist on my 1989 and the connectors are completely different. Thanks ,Jeff Edited October 15, 2013 by jbeary (see edit history) Link to comment Share on other sites More sharing options...
Guest Richard D Posted October 15, 2013 Share Posted October 15, 2013 How is your car shifting? My 90 coupe had started shuddering when up shifting under light throttle. Mostly from 2 to 3, I was thinking that at 138,000 miles a transmission overhaul was in my future. Turned out it was just the vacuum hose that wemt to the tranny on the drivers side. I noticed it about a month ago while I was chasing another problem ( bad crankshaft position sensor ) hooked it back up wnf car now shifts like new. The rubber hose connects to an aluminum pipe going to the transmission, the modulator ( I think )Good luck, perhaps someone with more information will chime in. Richard Link to comment Share on other sites More sharing options...
harry yarnell Posted October 15, 2013 Share Posted October 15, 2013 Cannister/ gas tank purge? Link to comment Share on other sites More sharing options...
zoltanb Posted October 15, 2013 Share Posted October 15, 2013 I have noticed that on some nutral safety switches(1990) vs 89 and 88 there is a vacuum connection could not find it in the fsm and am not sure of what it does. I looked at a replacement nss it did not have a vacuum conection, could it have been the wrong part? Link to comment Share on other sites More sharing options...
jbeary Posted October 16, 2013 Author Share Posted October 16, 2013 Thanks for the feedback gentlemen. The modulator is hooked up to a short hose through a metal line going to the intake. This is the same on my 91 and 89 so that's not it Richard. And the vacuum line that runs to the purge canister runs in the plastic channel under the air filter so that's not it either. Again, thank you both. I should have mentioned these before along with the cruise servo. I also should have mentioned that the pics are with the driver side wheel off. The first pic is justified horizontally when it should be vertical. The second pic is justified correctly and you can see the cv boot on the left and the hose is hanging on top loose. The poly line is actually wrapped in with the wire bundle terminating at the transmission connector. Since I can see the linkage but no neutral safety switch I say that's a good bet. I will check into that and let you all know. I'd have to look at Barney's data to see if all of the polo green Reatta's were built about the same time and if that's the case maybe someone with a very late production model can confirm the presence of this line is on theirs. My 91 was in the last 150 or so built and I've noted that it has the extra wiring for the 16 way seats where my 89 does not. The build on this car is so different from my Grand National. Truly "hand-crafted". Thanks again for the help guys. Link to comment Share on other sites More sharing options...
D-a-n-i-e-l Posted October 16, 2013 Share Posted October 16, 2013 Looks to me to be a breather/vent hose for the tranny. If it is not resolved by the time I pull my engine I will look into it a little deeper. Link to comment Share on other sites More sharing options...
harry yarnell Posted October 16, 2013 Share Posted October 16, 2013 I have a neutral safety switch (the one that goes on the tranny shifter shaft) with a vacuum port on it. Not sure what vehicle it came out of, but had to be a Reatta or a Cadillac. Link to comment Share on other sites More sharing options...
zoltanb Posted October 17, 2013 Share Posted October 17, 2013 My 88 and 89 did not have it but the 90 did never could find it in the fsm. Link to comment Share on other sites More sharing options...
D-a-n-i-e-l Posted October 17, 2013 Share Posted October 17, 2013 Does not sound like gm production falsify to use two separate parts to accomplish the same feet. Guess it has happened once or twice. Link to comment Share on other sites More sharing options...
jbeary Posted October 17, 2013 Author Share Posted October 17, 2013 True dat Daniel. Thanks again you all. Will look this weekend and post a reply. Link to comment Share on other sites More sharing options...
jbeary Posted October 21, 2013 Author Share Posted October 21, 2013 Found the nipple on the underside of the neutral safety switch. This is hard to see and I had to pull the wire out the loom and then of the way so I could see where to put the new hose. Thanks so much for the help everyone. I never would have found this and the car runs better as a result. Curious about how this neutral safety switch works. Normally a nss allows cranking and starting in neutral and park only. I realize at least two of these wires provides feedback to the digital dash. This one looks like it does a lot more. Anyone care to comment on what the vacuum is used for? Would failure of this switch cause cranking but not starting? Link to comment Share on other sites More sharing options...
Ronnie Posted October 21, 2013 Share Posted October 21, 2013 Could you post a photo of the neutral safety switch that has vacuum lines going to it? Link to comment Share on other sites More sharing options...
Guest Mc_Reatta Posted October 21, 2013 Share Posted October 21, 2013 I expect the hose is a vent hose for the tranny as suggested earlier. The switch probably seals it off when the tranny isn't in neutral or park so internal pressure isn't affected. Then opens it back up when car is in neutral to vent the pressure.This vacuum function won't affect starting at all. Electrical failure of the switch could prevent cranking and operation of the automatic door locks, but wouldn't cause a cranks but no start condition. Link to comment Share on other sites More sharing options...
Guest turbofish38 Posted October 23, 2013 Share Posted October 23, 2013 That hose is for the cruise control vacuum release. Kind of a redundant back up feature so when the cruise release circuit is open the sudden loss of vacuum doesn't cause it to surge. And it is not connected to the NSS. Your NSS is mounted to the transaxle. On some Cadillacs there is a vacuum port on the column or shifter mounted NSS that is for the automatic park brake release. Link to comment Share on other sites More sharing options...
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