I know that alot of people have done this before. However, I`m trying to decide which is the best route for the vacuum line replacemnet.

Here are my questions:

1. How long does it take? (Time wise 2hrs, 5hrs or a day etc...)

2. Which vacuum tubing should I use, Rubber or Silicone tubing?

3. What size tubing is needed? (3mm, 3.5mm or 7/64, 3/16 etc...)

4. How many feet of this tubing do I need? (25ft, 50ft, etc...)

5. Where can I buy this tubing and what`s the cost?



Any further info would be greatly appreciated

Thanks again,
Andre

 

I'll tell you what I did and hopefully that will help. I used OBX silicone hose for the vacuum lines (4mm), the larger vacuum lines (6mm), the turbo coolant lines (10mm) and the brake booster hoses (10mm). I ordered the squeeze clamps from mazda that are currently on some of your vacuum hoses (I can get the P/N's if you want them). I re-used the squeeze clamps from the brake booster vacuum line when I replaced those, and I used the same clamps for the turbo coolant lines.

I think a lot of people use 3.5 mm hose in place of the 4mm. The thing that bothers me about 3.5 is how tight it fits. It seems a little too tight for the plastic nipples on "heat baked" solenoids, the 4mm fits snug, and the clamps do their job quite well.

Recapp:
OBX silicone hose - reason: (local speed shop carries it and quality is as good as some other brands that will be recommended to you.)

4mm, 6mm, & 10mm sizes

squeeze clamps from Mazda (there are three different sizes - two for the vacuum hoses & one for the brake booster and turbo coolant lines).

I recommend doing the Throttle Body coolant delete, remove intake butterflies, remove emissions crap (if applicable) get the efini Y-pipe ( if staying with stock twins) and replace anything rubber with silicone!

If you need a reference, look here: http://www.robrobinette.com/hoses.htm

 

it can take anywhere from a few hours to a few weeks depending on whether or not it runs properly after screwing around in there i'm not kidding about this. be prepared to have the car not running right and dealing with it if a line gets crossed during the procedure.

just make sure you get some high quality material - the viton stuff from high temp silicon is actually really nice high quality stuff, but its a bit pricey. the stuff from hose techniques is nice too. don't touch the brake booster hose since it has something inside of it. also don't touch the 2 lines on the turbo with the pills. leave them stock.

turbojeff also made a good recommendation on this lines coming out of the turbo - leaving them rubber if yours aren't in too bad condition. the reasoning is that those lines might see some oil spray from the turbo and rubber deals better with that.

good luck.

 

quicksilver_rx7

Thanks for the quick response...If you can supply those part #`s for the clamps that would be nice... Also is black silicone tubing accessable because I see alot of peole having red and other colors..

Thanks

Andre

 

The hose that connect directly to the brake booster has a check valve inside of it. I replace the stock hose with silicone and just took the check valve out of the old hose and put it inside the silicone hose. Please note that this is a one-way check valve and if turned the wrong way will yield no power-assist when braking. If you get it wrong, just pull the hose off and flip it around. I would test the brakes before getting out of your driveway.

The wastegate and pre-control lines have brass pills insided of them (controls pre-spool and boost levels). I replace mine with silicone and swapped the pills into the new lines. Oil breaks down silicone if exposed to it in large amounts. I personally think that the small amount that gets in these lines will have no effect on them. Opinions vary on this.

4mm hose clamp: p/n 9928-30-800 looking at my records; looks like I used about 35 of these. Note that my car has the "simplified" vacuum system. Staying stock will yield the requirement for more clamps.

6mm hose clamp: you should have these already on the engine.

10mm hose clamp: p/n: 9928-31-500 looks like I used about 8 of these

you can order black, red, yellow, blue, green, etc.. from just about anyone that carries silicone hose

 

thanks again...i`ll keep you informed with my progress.

 

sounds good. I look foward to hearing about the progress and hopefully seeing some pics.

 

Andre,

I used the kit from hose techniques. IMO viton is expensive and the hose techniques version is a good silicone kit. The time spent will vary on how easily your old lines come off. Just go slowly and be careful when removing the old hoses. I would use a razor blade and slowly cut into the hoses (on the nipples) and gently cut the lines until you can get them to pry off. Do not force them off. This will take a little time. Just take one off, use it for a reference, cut new hose, and replace. I didn't use clamps on my lines, but that is another argument. Good luck.

Charlie

 

you have to be careful when you do this. some people have wound up having boost issues b/c the pills didn't sit inside the hose tightly enough.