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Vacuum Line replacement with high temp silicone lines

43K views 91 replies 23 participants last post by  iowagold 
#1 · (Edited)
My vacuum lines were old, hard, cracked, and brittle (20+ years in a hot engine compartment will do that to you) so it was time to replace them. Doing it while the engine was out just made it that much easier, this was part of my replacing the manual transmission project. If you still have the original equipment lines it's time, well it's probably past time to replace them one and all.

I ordered these on eBay
  • 3 meters of 6mm green high temperature silicone line
  • 3 meters of 5mm red high temperature silicone line
  • 3 meters of 4mm purple high temperature silicone line
  • 3 meters of 3mm blue high temperature silicone line

I used almost all of it, I could have ordered 2 meters of the 4mm and 3mm but it's not expensive and I didn't want to run short. I used different colors for different sizes to make it easier to keep track of the sizes, and it looks good.

Advantages of the silicone, it is resistant to heat and most things under the hood except fuel. Don't use it for fuel or fuel vapor lines.

If you have a 2wd you won't need nearly as much 5mm

See photos:





 
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#3 ·
The throttle body hose goes to the evap cannister under the master cylinder see the photo of the evap cannister, it's the black fuel line connected next to the air filter. Your's won't have a filter there, it will have a line going to your air intake system. You should use a fuel line because fuel vapors travel through that line.

Those VSVs are for the 4x4 transfer case actuator. See the red vacuum hoses in my photos of the back side of the engine. They have to be connected to the proper locations, I had mine numbered so I don't have an exact photo of where they go. I'll find something and post it shortly.
 
#7 ·
Looking back on it, to prevent confusion for the 4x4 actuator, order different colors of 5mm for each line to color code it and make it easier to hook up right.
 
#9 ·
The silicone vacuum lines are heat and rot resistant and using different colors allows color coding. Replacing old deteriorated lines if you have leaks, will improve performance whether you use silicone or stock lines. Preventative maintenance is a another reason, if you replace the lines you can prevent many mechanical problems that will cause several different codes to open on the OBDII depending on the systems effected.
 
#10 ·
Are they all the same size? Or one/size color for one specific line. Another size/color for another hose etc? I think it's a cool upgrade but save us the "figuring out" head ache. In other words; Share your knowledge! :nerd I know I've done this in this forum hundreds of times.
 
#11 · (Edited)
I initially did this one color for each size as follows.
  • 3 meters of 6mm green high temperature silicone line
  • 3 meters of 5mm red high temperature silicone line
  • 3 meters of 4mm purple high temperature silicone line
  • 3 meters of 3mm blue high temperature silicone line
Most of the red is 5mm is used on the 4x4 actuator if you don't have a 4x4 you can buy just 1m and have enough.

I had problems with getting the hookups right for the 4x4 actuator so I went back and color coded it.
Red 5mm - hose from the connector off by itself on the actuator (left it red actually because this one is so difficult to get to with the engine installed) to the lower position on the passenger side vsv
Orange 5mm - "0" on the actuator to the upper position on the VSV closest to the driver
Lime Green 5mm - "2" on the actuator to VSV this line splits and one goes to the bottom of the VSV closest to the driver the other end goes to the top of the other VSV
Purple 4mm - unmarked on actuator to intake vacuum splitter
Purple 4mm - intake vacuum splitter to MAP sensor
 
#16 ·
#18 ·
I noticed that this did not include the power steering pump vacuum hoses for the idle up so here is that info.

The vacuum fitting (17630 - VALVE ASSY, AIR CONTROL) is where the vacuum lines attach to the power steering pump.

The vacuum line listed as 17344G - HOSE, AIR, NO.4 attaches to the above and runs to the hose barb pointing towards the engine on the rigid vacuum pipe (17361G - TUBE, AIR(FOR IDLE-UP). This rigid pipe is located above the power steering pump.

The vacuum line listed as 17345B - HOSE, NO.5(FOR IDLE-UP) attaches to the above and runs to the hose barb pointing back towards the power steering pump on the rigid vacuum pipe (17361G - TUBE, AIR(FOR IDLE-UP). This rigid pipe is located above the power steering pump.



In this picture you can see the red vacuum lines coming off vacuum fitting 17630, and it is easy to see the line running from that fitting to the hose barb pointing towards the power steering pump. The other is blocked a bit by other vacuum lines but you can see the red line attaching to the hose barb pointing towards the engine.
 
#19 ·
I had made one of these vacuum line diagrams before based on a hand drawn one I got from a nearby Toyota dealership maintenance department however, it was way off so I deleted it, here is the real thing.

In the below illustration it shows vacuum lines "0" and "2" location on the VSVs, that was key because two of the vacuum ports on the transfer actuator are labeled "0" and "2" the other ports are unlabeled. The unlabeled port next to "2" on the transfer actuator is a smaller diameter than the others and that matches the size coming from the intake manifold. The split line that goes to ports "1" and "3" on the VSVs is left going to the lone port on the secondary vacuum chamber.

I did confirm that this works on my 99 RAV4; I don't know if all the models are exactly alike.



 
#20 · (Edited)
A guide for the easier way to do get to get to the vacuum actuator to install the vacuum lines.

Materials needed (you can use different colored lines, these are just suggestions)(I got the colors and great quality hoses from ebay.com):
2 ft - 5mm black silicone high temp vacuum line
2 ft - 5mm green silicone high temp vacuum line
2 ft - 5mm blue silicone high temp vacuum line
2 ft - 3mm red silicone high temp vacuum line
Reuse the vacuum line splitter and anti-chafe tubing

Tools needed:
- long reach needle nose pliers
- jack
- jack stand

Procedure:
- Jack the passenger side up at the "frame" just behind the engine to lift the tire off the ground and place a jack stand under the car for safety. Set the brake, chock the rear tires. The reason you jack it up is to make it easier to work under the car and to drop the tie rod down so you can get your arm in there.
- Assemble your vacuum lines using the anti chafe material provided or replace with new material, remember it gets really hot here so if you are replacing it use something heat resistant.
- Lower the assembled hoses behind the engine roughly into place.
- Install the blue line (#3) first, this is the most difficult and you are probably not going to do it if you have large arms and fingers. The location is under the black (#0) vacuum line, you cannot see it you have to feel for it, you will feel one of the mounting bolts move your hand around until you feel the vacuum port. Grab the hose between two fingers like holding a cigarette and push it on, it is not an easy job and it can be frustrating but it is doable.
- Using long reach needle nose pliers put the other hoses on starting at the 3mm hose
- Once the lower hoses are on, connect them to the appropriate locations on the VSVs according to the diagram
 
#21 ·
eodgator,
Your shopping List in your original post: 3-mm, 4-mm, 5-mm, 6-mm.: these are I.D. (inner diameter) dimensions, correct?
 
#22 ·
Yes, inner diameter.

If you follow how to get to the actuator it makes it a lot easier. You may have to remove the front right tire.
 
#23 ·
My vacuum lines were old, hard, cracked, and brittle (18 years in a hot engine compartment will do that to you) so it was time to replace them. Doing it while the engine was out just made it that much easier, this was part of my replacing the manual transmission project. If you still have the original equipment lines it's time, well it's probably past to replace them one and all.

I ordered these on ebay
- 3 meters of 6mm green high temperature silicone line
- 3 meters of 5mm red high temperature silicone line
- 3 meters of 4mm purple high temperature silicone line
- 3 meters of 3mm blue high temperature silicone line

I used almost all of it, I could have ordered 2 meters of the 4mm and 3mm but it's not expensive and I didn't want to run short. I used different colors for different sizes to make it easier to keep track of the sizes, and it looks good.

Advantages of the silicone, it is resistant to heat and most things under the hood except fuel. Don't use it for fuel or fuel vapor lines.

If you have a 2wd you won't need nearly as much 5mm

See photos:
A view of the engine showing vaccum hoses in place - https://drive.google.com/open?id=0B0N4qdhM8CoaUGxCR2RaS2ZCdms
A view of the evap cannister - https://drive.google.com/open?id=0B0N4qdhM8CoaMlhvaWJCQTg0QUU
A view of the engine compartment - https://drive.google.com/open?id=0B0N4qdhM8CoaWk5qTmtQbjdBYTQ

Where did you buy all those silicone high temp vacuum lines? Summit Racing, JEG'S, Amazon?
 
#24 ·
mensajero,
It's in your very Post (Post #24 ) in the portion you quoted: " I ordered these on ebay".

Amazon has them too.
 
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#25 ·
I picked up the vacuum lines on eBay from a couple of different sellers but the heavy duty vacuum lines I got from hardline_co were the best quality and you can order in various increments.
 
#26 · (Edited)
eodgator, What am I missing?
How long ago did you get those heavy duty vacuum lines from hardline_co on eBAY? Today hardline_co only offers on eBay:
1/ 5-ft. increments, period, $9.98-per-5-ft. No other lengths.

2/ Colors are all 5-mm. No 3-mm, 4-mm, 6-mm. ??

QUESTION: Do us a favor? What's MINIMUM length of each 3-mm, 4-mm, 5-mm, 6-mm we can squeeze by with on RAV4 manual transmission 2WD (FWD)?
 
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#27 ·
eodgator,
How long ago did you get those heavy duty vacuum lines from hardline_co on eBAY? Today hardline_co only offers 5-ft. increments, period, $9.98-per-5-ft. Is that same as what you purchased? No 1-ft. increments, just 5-ft. Thanks for posting price/source/Vendor!
Originally I bought 3 meters (roughly 10') of each size just because I wanted to make sure I had enough, and it's not very expensive. When I redid the transfer actuator I wanted it color coded so I got 2 ft of each color which was just the right length. At that time the seller was selling by the foot. If you contact the seller and tell them what you need he may make custom lengths if not, look around on the eBay and the rest of the internet and I'm sure you'll find a good supplier.
 
#28 · (Edited)
eodgator,
Yupp, already contacted hardline_co on eBAY.

What are absolute MINIMUM lengths of ea. size for 2WD (FWD) manual transmission?
 
#29 ·
Hey all, looking to swap out my old vacuum lines next weekend and I have a few questions:


On my rav, the line coming off the throttle body hits a sensor mounted on the air filter before landing on the charcoal canister - what is that sensor for? I'm also having an issue when I gas up, the fumes are feeding out of the gas cap instead of the canister. The lines coming off the throttle body are not fuel lines either, so hopefully I can clean that up at the same time.


I'm having low idle at cold start, sometimes so low that I need to give it gas for 30 seconds or so so it doesn't stall out. Tried cleaning out the throttle body but it hasn't helped. the idle issue is only on a cold start.



is it possible to replace all these lines with the engine in the bay? it looks like a few of them go pretty deep in there, but I'd really like to replace them all at once without taking the engine out.


Thanks for the write up! excited to finally get the center diff lock working.. :)


cheers!
 
#30 ·
Elliot--
1// Did you follow this video? I get great results. If not, start over and do again. Use old rags & toothbrush to clean Throttle Body per Scotty's instructions. 2// Install new OEM Genuine Toyota PCV Valve-- they're inexpensive but should be R&R'd every 2-3 yrs. Don't go El Cheapo on crummy aftermarket. 3// Clean MAF Sensor (removed from vehicle) if you have one.

P.S. Please add your year-make-model to your "Signature" so we know at-a-glance what we're advising. Your video:


 
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