DIY How to Replace 4WD Vacuum Actuator Switch on a Blazer S10 Jimmy How to Troubleshoot 4WD Issues
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- čas přidán 22. 08. 2024
- Replacement Blazer, Jimmy, S10 4WD Vacuum Actuator on Amazon - amzn.to/36nh8r4
Replacement Transfer Case Vacuum Switch on Amazon - amzn.to/2EgB7x4
This video walks through the process of diagnosing a common 4WD issue with a 1998 Chevy Blazer, GMC Jimmy, S10 and more. In this video I demonstrate how to replace a vacuum actuator switch that is on the top of the transfer case. I also end up finding and repairing a vacuum leak which ended up being the problem. The vacuum lines should be completely flushed on this vehicle and there is likely a bad seal between the transmission and the transfer case. The vacuum actuator may need to be replaced in the future also due to the amount of transmission fluid in the actuator itself.
Replacement Blazer, Jimmy, S10 4WD Vacuum Actuator on Amazon - amzn.to/36nh8r4
Replacement Transfer Case Vacuum Switch on Amazon - amzn.to/2EgB7x4
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Replacement Blazer, Jimmy, S10 4WD Vacuum Actuator on Amazon - amzn.to/36nh8r4
Replacement Transfer Case Vacuum Switch on Amazon - amzn.to/2EgB7x4
Hi idk if this has any chance of reaching you but I still have a 2000 Jimmy as a winter heater and my 4wd light is on and it’s not shifting into 4Hi and the selector is stuck blinking on 4Hi. But when you press the selector you can hear a strong buzzing at the transfer case it tries to switch to 2hi but it doesn’t and just goes back to blinking at 4Hi. Did your transfer case switch make a buzzing sound when it was bad?
I had a 1991 Jimmy that used this same vacuum actuator switch. I replace 3 in 5 years and it always failed in deep snow towing the snowmobiles, very frustrating. The dealer did two under warranty and we did the third one on my friends hoist and said we need to find why these are getting all gummed up and the ball was ceasing. We traced the hoses on the top of the switch and found one line was a breather vent that ended behind the grill, in front of the battery with a foam filter on the end so this was intended to allow clean air in the tube. A closer look we found whoever installed the battery tray at the factory had pinched the hose and put a big slice in the hose which allowed it to suck in dirt. we cut the hose before the slice and stuck the filter on the end. No problems for the remaining 15 years I owned the vehicle.
Mark... link to "how to find the vac leak" please... vid link does not seem to exist. Thanks.
nice video,, i have a 03 s10 ZRT,, had same issues,, not sure if i commented on this video? already.. .. but if you take the passenger headlight out..you can see the actuator under the battery and test it Without taking out the battery.. helped me alot,,, figured i would share
Great idea, they pop right out, gonna try that this morning.
THANK YOU
Thanks for the video. I just recently started having problems with my blazer staying in 4x4. It would go in then pop out as soon as I gave it any gas. After watching this I figured out I had a pretty bad vacuum leak from the blend door actuator, where the line runs into the drivers fender. I haven't been able to switch my vents in years. I guess it was rotted and just creating enough vacuum to switch into 4x4 the past few years until it finally broke off completely. Fixing this took care of a random rough idle/misfire, my poor gas mileage, poor shifting, and I can finally use my defrost again. All gremlins I've spent money and years trying to track down. Amazing what 50¢ worth of vacuum house can fix.
Sir, I need to replace this other hose too
How did you find the vacuum leak ?
Hello, used O2 sensor socket, it's thin wall deep socket fits perfect + the socket protects the hose connections!
Can you post a link to the vacuum leak find please?
Thank You SOON Much,I just got my blazer and live in Minnesota So I Need 4wd a lot of the year,You showed me A Great deal of where my problem should be,Thank You SO Much!!!!!
Where’s the link to the vacuum problem
Any link for how to find a leak?
Man if the fluid got into the rest of the vacuum system that’s a big job. I replace that part with the original ACDELCO part only every 2 years.
Mine was stuck on 😬. It released as soon as I pulled the vacuum line off the actuator. The cable felt really easy to move, haven't gone through the whole thing yet, feels like the cable might be broken.
Thanks for this video, man! Just bought this little truck and I'm very unfamiliar with it. This was a great start 😊. Thanks!
Great video. My 98 LT is doing the same thing-the light will show '4-Hi' but front doesn't engage. I've also noticed my cruise control intermittently working so probably vacuum leak. I've replaced the vacuum lines in preparation for Missouri winters but I still have to go to 'N' and 4-Lo to get the front to engage. I really hope I don't have a bad front seal leaking ATF into the front differential....it'll wreak havoc on your HVAC.
my truck is the same way. auto 4 wheel drive will go in without being in neutral. I think this is how it is supposed to work. it will not engage in 4 hi or 4 low with out being in neutral first then pressing 4 hi or 4 low then shifting to drive then it will engage.
@@westside_tints8197 I took the encoder motor off-and used a wrench to manually turn the transfer case. It locked in most of the time, but with the encoder motor on it will not lock in. No error flashing lights on the push buttons. I think we both have something bad in the transfer case that's not allowing it to smoothly shift. My front end locks in, but no power going to it.
I had the same problem last week. When I selected 4h or 4L the indicators would only blink and never lock. Mine is the 4 button so the VAC Switch is on the firewall above the distributor easy to get at. I first pulled the line going to the axle actuator, pushed 4x4, no vac. Next pulled vac feed, no vac. Found a 1" gapping hole in the line right at the manifold tee. Fixed! Also improved my idle!
Can you link the vacume vid fix please?
awesome vid. I have a 99 s10 4.3 and it started making a noise. It stops in 4wd of course. I will have to look at this switch. I think anything besides that and its not worth it as I Might be looking for a new truck come spring. Went nuts trying to clear my check engine codes (vaccum leak) and once it was done this happened. yay me
Excellent video, wish you were my mechanic!
Thanks. I now feel like I can save an extreme amounts of money than what the repair shop wants to fix my 4x4
I have a question about my 1998 s10 4.3 4x4, how do the vaccum lines hook up? do they all go together or..? I replaced them didn't take a picture, truck runs fine but no 4x4..thanks.
Nice video, nice how you show how you get to the tight areas and locate what we need to find and what the possibilities are from visual signs like the trans fluid in the hose , Thanks
I had had trailblazer with electronic actuators. Lovely. Now I have an 86 s10 blazer. NIGHTMARE. But way cooler lookin
When I changed out mine, I cut a hole in the floor right above the switch! Then made a patch to cover the hole! Easy pleasy!
where about did you cut the hole and how?
Haha nice to see another crazy besides me. Ive done the same for fuel pumps.
Hreat video man, helped me save 1400 at the shop in my 00 zr2
haha thanks for the battery notes! I've heard some bad stories. Never leave that ground on there by itself!
Great video this should help me with my 1999 Chevy Blazer 4x4. Thanks
Any reason you did not replace the bulb in the 4 hi button?
Thanks for the video and trouble shooting tips. Replaced most of the easy part and it worked fine....
Thanks Mark just wasn't sure if that would still be the problem
nice, i wanted to see the fixed vacuum line
***** thanks good job
I'm having issues with my 2001 Chevy Blazer 4wd. When I press 4hi I hear sound underneath the truck that I assume is an electronic motor, but 4hi never kicks in and it's light continuously blinks. When I select 4Lo I hear a loud 'thunk' sound underneath the truck and the 4Lo engages, but its light blinks continuously, too. I have checked to see if my cable is seized (it is not) and if the vacuum diaphragm is damaged (it is not). I looked for the vacuum valve on the transfer case, but I think my Blazer only has the electronic vacuum actuator that is located near the distributor. I tried a new electronic vacuum actuator but that didn't fix anything. I have began to replace some various vacuum lines that were dry-rotted. I have a small amount of vacuum pressure going to the electronic vacuum actuator, but I don't know if it's enough to engage the rubber diaphragm.
When I have the truck on and the battery removed, I have no movement of the rubber diaphragm or cable when I press 4hi or 4Lo. Does anyone have any ideas or suggestions?
+David Meeker I just fixed mine and had to replace almost everything. Jack up the car, remove the battery and lubricate the cable on both ends. See if you can get the front wheels to spin while pulling on the cable with your hands. You also can see if the actuator is moving enough like in this great video. It is best to engage the 4wd in neutral first. Also remove the vacuum line to see if there is vaccuum. Finally you can use an hollow adapter to join the vacuum lines together or brake line to engage the 4wd and bypass the vacuum switch. Check the vaccuum over by the ABS system as this is where is originates. Good Luck
Thanks for that amzn link. 👍
I think the negative is to be removed first or replaced last so it can't arc out inside the battery and explode. 😁
hey mark just wanted to let you know that i fixed mine it was the actuator vacuum line thanks a lot though
My 2000 blazer is locked into 4 wheel drive. Any help would be appreciated. Transfer case clicking lights on switch showing correct actuator works. Still in 4 wheel drive.
So you try to put in in 2wd and the Tcase clicks but never goes? Could be the encoder motor. Have a look at this video and try rapping on the encoder motor to see if it will disengage. czcams.com/video/mkrSMKA_EBc/video.html
Will the actuator be on the same place as? It was only Jimmy on a Chevrolet. S10 ZR2.
I had a 1999 chevy blazer my 4x4 panel blink when I put the switch but then shut off, and on the Dashboard had all wheel drive service,. I try get the vacuum switch but mine don't have it,. Had a single hose connected
For some reason the vacuum troubleshooting link doesn’t show. But I’m curious about one thing - my truck (98 ZR2) is giving some grinding noise when engine vacuum is low (higher throttle), and it’s related to 4wd. Does the actuator pull the cable to disconnect the transfer case, or to connect it? I thought vacuum was necessary to enable the 2wd operations. Mine is not in 4wd, and the grinding is occurring...
Was it also idling rough because of this vaccum leak? Mines running rough...
Great video, hope to diagnose my 97 blazer soon.
Thanks!
I have a 2000 gmc jimmy. All new vacuum-lines and the vacuum actuator is good. I am in 2hi and I can shift into 4Auto but when I hit 4hi it blinks and then switches to 2hi. When in neutral and shifting to 4low it will flash 4low then flash 2hi then all the 4wd lights shut off and the service 4wd light comes on. Then you can turn of the car and right when you start it if you hit 2hi the service 4wd light turns off and shits to 2hi. This process can be repeated. When the service 4wd light comes on the error code is error C0387. Please help!
This capsule under the battery only contractwhen tou drive or is it when you start the car?
Your video didn't show how to change the vacuum aacuator
Does it matter the order in which the vacuum hoses go onto vacuum actuator if replacing those hoses?(order on the three connector hose fittings for the triangular shaped thing)
i just purchased a 1998 S10 Blazer, My Vacuum diaphragm as exploded from the last owners negligence, the battery leaked all over and the corrosion ate the rubber seal
hey Mark, Pls upload hwo to find the vacum leak!!!!
For me, the reason the switch sucked up fluid is because the transfer case overfilled due to a bad input shaft seal slowly leaking ATF into the transfer case. Eventually it overfills as the user puts more fluid in, and bam you're sucking in fluid. I will have to replace the input shaft seal first and then replace the switch and so on. The ATF made it into my 4wd actuator and compromised the rubber membrane but luckily as far as I know, none in the HVAC actuators behind the dash or in the vacuum reservoir. I see in the description that you noted this, but was this after you replaced the seal or were you going to replace the seal soon after?
Replace your input seal on transfercase, when it goes out it drains transmission and puts atf in transfercase
how do you flush the vacuum lines?
I have an 98 blazer with the 4.3 vortex and I have been having problems with my 4 wheel drive what it's doing is it will switch to 4lo and 4hi but when I try to switch it back to 2hi the front driver side will come out but the passenger side in the front is still stuck in 4 wheel drive it causes the vehicle to vibrate really bad what do you think it is
Someone PLEASE help me!!
My 99 Blazer has all of the 4x4 lights on and when I press a button it wont do a single thing... not too sure what the deal is someone please help!!
Hi Mark, This question is not related to this video but you may be able to help me out. My vehicle had at least 2 owners before me & some of the repairs, well you know where this is going. Anyway I have the same radiator cap on my radiator as yours and I cannot get it loose. I had a Chevy van that was the same & needed a wrench to get it off. But this one is plastic & my concern is that some sort of adhesive may have been used & I do not want to crack the cap or more important the radiator neck. Is this common for this vehicle?
I replace the vacuum actuator on my 88 s 10 blazer and it still seems to go back into 4 wheel drive on its on after a day or so..at least the indicator like on the floor comes back on saying its in 4 wheel drive
HELLLO! i want to convert my 1991 s10 blazer 4x4 vacuum 4wd actuator switch to electric switch is there a way to do this ?
I have a 1998 s10 blazer and last night I went to put it 4 high and had no 4 wheel.I was told to check for a vacuum leak or the piece I don't remember what they call it and its on the transfer case cost $49.99.It engages in the truck and you can hear it click under.So would this just be a vacuum leak?
Nice demo, Mark.
Good Video, Thanks!!!
Amigo excelente trabajo mi blazer 2002 tiene esa falla me puedes indicar hacia donde salen los tubos de goma gracias
awesome man! Looking at a zr2 hope its worth the trip
Thanks.
You're welcome
I got a 2001 chevy blazer I used 4x4 once but when I went back to 2hi it started to make a noise in the right front...it sounds like gears not fully disengaged but the noise seems to be more closer to the tire than it does under the vehicle...the noise is similar to riding on bump strips on hwy at normal speed and as I slow down noise gets louder ...if its still partially engaged should I not hear noise across entire front end...I also checked my actuator and its dry n it does move with ease....this is my daily driving vehicle and I need some advice real fast as I have it in air in the garage ....also could possibly try and disengage ..if that is the problem ...while its not running
hey, did you figure out what was wrong? my 2000 blazer has the exact same problem.
Switch is like $15 and easy to change!! I had clicking but I heard it gets worse and this was the 4x4 switch which has a ball at the end and it gets sticky and doesn’t disengage good and grinds up the gears on a shaft. If not fixed ASAP can do serious damage!
Pregunta espero me puedan ayudar tengo una blazer 95 y me dijo el mecanico que el humo se debe a que esta pasando aceite del transfer al motor sera cierto?
Great video, thanks for the tips!
hello friend, my blazer 1996 has the line well diaphragm but it does not arrive empty to the actuator. What can be? I need your help, thank you. because there is no vacuum in the line that drives the actuator?
very helpful DIY.. Thank you and Kudos to you sir!
Great video. I have a question, what would cause my 4WD fuse to blow? When this happened I got no light indicators on 2Hi, 4Hi, 4Lo buttons and it felt like 4Hi was engaged. I disconnected the sensor wire by the transfer case and the fuse didn't blow and the lights are back and buttons appear to be engaging, but when set for 2Hi it doesn't seem to stay there, feels like it slips back to 4Hi. Thanks!
+Bill H sounds like the encoder motor on the transfer case.
I have a 2003 sonoma 4x4 that's stuck in 4 low.The light on the 4x4 switch for 4 low is lit but just just flashes when I push either 4 hi or 2 hi and there is no audible noise coming from either the tccm or the transfer case shift motor. It's my understanding that the actuator valve under the battery engages the front diff and the vacuum valve on the transfer case sends vacuum to the actuator under the battery but would either of those valves cause the problem I'm having or should I be looking at the TCCM or possibly the shift motor on the transfer case.
Did you find your issue?
My actuator feels like it is full of air I changed the switch and the front differential gears for the 4x4 but now it's not pulling the cable
I have a 1196 s10 blazer 4,,x4 I manually took out of 4hi because cable broke now when I first Crank it up and drive it it drives fine after it warms up I lose first and overdrive
My actuator activates as soon as I turn the car on , but 4x4 does not work at all on any button. Only after i turn the car off, does the actuator deflate back to normal position. As soon as i turn the car on again, vacuum kicks in and pulls cable out. Any ideas?
really helpful ! thanks .
I have a 2004 Chevy blazer I bought a new switch and mine still does not work the lights will not come on a all and can't hear the switch if you could help
So am I understanding correctly that, on these trucks, the transfer case is essentially always in 4WD mode and when you press the 4WD HI button you're just engaging the front differential to the front driveshaft?
@@nogripes Ohh.. okay, so two steps. So if I see the diff actuator engaging fully then I know it's something wrong with my T-case? :S
@@nogripes
If the front dif actuator doesn't work, does that mean no 4wd at all, or just that the front dif is just an open dif but still gets power from the shaft?
I just pulled out my battery tray and found my actuator torn to hell so I'm hopeful that's all it needs. I checked the vacuum on the line as well and it has a vacuum but didn't feel like a whole lot just putting against my thumb How hard should it pull?
Blood on the knuckles transmission fluid and freezing rain great day in Dixmont
Says the Duke of Dixmont
I have a 1997 blazer really help thanks!
I have a 97 bravada smarttrak I’m not 100% sure what it is but the truck feels heavy and feels
Like the engine trying a lot just to move and im only gettin 16 mpg on the highway. How would I know if my truck it stuck in 4low? I have no 2hi,4low or 4hi buttons
Where's the vacuum leak video?
My 4hi and 4lo lights keep coming on by their self and also when i take off something feels likes its wrong dont know where to go or what to do to fix it?
Excuse me, sir. I have the same problem on my jimmy and I'll get around to fixing it, but is it possible for right now to lock the diff manually by pulling the wire myself? Lots of snow up here.
***** Thank you very much!
A deep socket works just find. Plenty of room.
what does that switch do? does it engage/disengage the 4x4?
I had no problems getting it out, camt for the life of me get it back in. New one or old one wont thread back in. Yes its in 2 wheel drive. I had it in 4 wheel and the button was hitting. Putnit in 2 wheel and dont feel anything in the hole now but it will not thread back in.
Hi sir! What year is your S10 ?
I have no leaks changed out switch on transfer case.. Transfer case makes the noise like it should but doesnt kick in
Is it sum what the same process with an 89 blazer
The link would not open for the vacuum leak
Great video!
I have a 95 it lights up when I start it then it goes off the it won't let up.could it be a vacuum leak?
My 99 jimmy 4x4 vacuum diaphragm is stuck in for my 4wd I can heard it switch in and out of 4wd
Thanks Buddy
When my 2000 S10 is in 2x it clicks, when I push 4x button clicking goes away but does not engage 4x. I replaced a corroded cable and have vacuum. I can hear it move back and forth. The vacuum boot looks fine. Maybe not enough vacuum...but boot is sucked all the way in. Otherwise bad vacuum switch...but I have vacuum? Any ideas? Thanks.
+Tyler Ubinger Sounds like your actuator gears are stripped due to the cable not fully releasing.
I have a 1999 Chevrolet Blazer Vortec 4.3l V6 4WD 4-door with the 4-button switch... My 2 HI, 4 HI and AUTO 4 WD works fine, but not the 4 LO. There is no click to hear and the light on the 4 LO button is only blinking. What is the problem?
I need answers too. What was it?
@@jeremylivengood3381 Still no function on my Blazer... I think, i have to live with it :-(
Pliz describe to me how the Pajero GDI (4m40 engine, manual transmission) 4Wd system work.
I am repairing one but without proper diagrams.
Can't access the video for vacuum leak
Any help would be thank full mine goes 2 H 4 H but not 4 Low what can I do thank you .
@@nogripes Thanks very much
Do u know if this is the same on a 97 1ton Chevy 5 speed 4x4?
How did you find the vacuum leak
second...!!! Hey Mark ^
Good job buddy
Sooooooo, pulled the battery and my actuator is stuck on. I think I've been driving in 4x4 and have destroyed my front diff as I now do not get any power from my front tires. Not sure how to check if this is the case though?
Thanks for the advice. I'm assuming that if the front driveshaft is turning but no tire movement it is the diff? If so I'd love some pictures, I have never worked on a diff before!
thank you