Today I decided to do a bit of a tune up with my 1999 discovery, and put in new spark plugs and plug wires. The car drive a lot smoother now, but for some unknown reason the brakes are very stiff and its hard to come to a stop. Before I changed the plugs the brakes worked fine, and had a lot of "wiggle room", and where very "spongy". I am pretty dissapointed now because im sure i did everything right when upgrading my plugs....

Now the weird part is, that after driving about 3 or 4 miles in the city( lots of lights to stop at) the brakes seem to work fine... but then the problem has come and gone through out the day. Anyone here have an idea why the brakes are acting funny on me?

 

Check the servo line that goes into the intake plenum. I bet it's broken

 

Uhmm... I am pretty new to this kind of stuff. sorry, but im not even sure you are speaking English here haha . How exactly should i go about doing that? Where would this be located? I have owned my disco for one year now, and this is the first thing i have done to my car, beside the basics like oil change, so i am still learning.

 

I hate to say it but changing plugs and leads has no connection whatsoever to the brakes or braking system, you have either disturbed another part of the braking system or it's a coincidence that the brakes are not working correctly. You will need to download a copy of the workshop manual, RAVE, and study the braking system as it's more complex than most other vehicles of it's age. (the D2 RAVE workshop manual is available on this forum)

 

The first time I changed plugs and wires I broke the brake servo vacuum line. I changed the wires without removing the upper intake. I put a pad on top of the engine and laid on it face down. At some point during that ordeal I broke the brake servo vacuum line where it enters the upper intake.

Ricky, I don't have my truck here or I would take a picture for you, but as you face the engine from the front, look at the left-hand side of the upper intake. There are two lines that connect to it at the front. One is smaller diameter, made of nylon (that many here mistakenly call brittle plastic) and connects to the upper intake through a connector that has a red ring around it. Check there.

If that line is broken there it would make braking much more difficult. It would also likely cause the Service Engine Soon light to come on. If it's broken there is an easy fix that can get you by at least temporarily. Take a look and let us know.

 

That would be my thought as well mln01

 

I'm having a hard time finding it without pictures, but is it detrimental if I drive my truck around for errands today?

 

 

You are looking for the hard plastic line that goes into the intake manifold with the red circle push connector. It's just in front of the passenger side valve cover breather hose.

 

My 1999 land rover appears to have the brake valve located on the driver side.