My signature line should show what I am working with. 2000 Disco II.

I am having a brake vacuum problem, I think. The basic symptoms are no brake assist at startup, slow recovery after heavy breaking (hit brakes, hit brakes again and almost no assist), and slow to build vacuum (I have about a 100 foot driveway and by the time I get to the bottom there is no assist. When I drive about another 100 feet to the stop sign, there is still no assist. Another block or so and I have assist), and a very long throw with resistance before brakes engage if on a panic basis.replacing my

Nothing untoward has happened to the truck.

The sole vacuum issue that I know of is the hard line coming out of the passenger front of the throttle body. I broke that little red ring and fitting with my knee replacing the coils a long time ago. I put HVAC aluminum tape over the hose and throttle body area and it is like concrete... I don't think it loses any vacuum. In fact, i have removed the fan and put smoke next to it and did not see any movement toward the tape/fitting. I don't think it matters, but I do not have the guide bolt on the upper intake (I must have lost it when I replaced the engine), so the hole in the valley of the upper intake is open.

Brakes have been bled multiple times in the prescribed manner and I am pretty sure there is no air in the lines.

Sadly, other than replacing brake pads and adjusting parking brakes I lack any knowledge about brake systems. Can anyone give me some guidance? I still drive it and it passes inspection but only because I drive like a grandma and the inspections are lax in my part of the world.

Truck has about 133k on it now.

Best,

Charlie V

 

what you could try is spray all along that vacuum line with carb. cleaner, if your idle changes you have a leak.

 

Check the vacumm line at the brake booster. Round black thing on the firewall opposite your pedal assembly.

 

Thanks Drowssap. I just checked that vacuum line on the front of my throttle body and it was leaking like crazy. I guess HVAC tape isn't made for engine repair (what a surprise!) and I'm going to have to order that little fitting in a moment. My patent will be denied.

Once I have that on I will try the carb cleaner.

Is there any issue with the guide post hole in the valley of the upper intake being uncovered?

I will report my success.

Best,

Charlie V

 

I ordered this doohickey.

 

Probably the best fix is to pull out the weird red plastic gizmo on the intake and tap it for a brass fitting and be done with it. No reason to use the factory fitting there.

 

Completely agree with that. I replaced the fitting right behind it with a brass fitting long ago but I couldn't find one that would work in the brake servo line (bought several) and I didn't have a tap big enough to thread a new hole. I'd rather have brass anyway so I'll have to check the offerings at Harbor Freight.

 

I will look for that today. The plastic and rubber on my truck is 14 years old and things just degrade.

 

I replaced that same dookickey a while back and I have some advice for you.

1) you will have to drive the old piece out. The best way to do that is with a long socket extension. Take off the intake tube and use vise grips to clamp the throttle fully open. Use the long extension and a hammer to drive out the old connector from the inside.

2) Use some grease on the outside of the new connector and the hole in the intake where it goes to help the new connector go in without breaking.

3) The new connector should also come with a small 1 inch plastic vac tube inside the connector. Leave that 1 inch plastic piece in while you tap it in with a hammer. That piece should prevent the actual connector from being damaged by the hammer because you are hitting it instead of the connector. After the connector is fully installed you simply take that small vac piece out and install the normal brake servo vac line in it's place.

 

Ace Hardware, or any local hardware store, sell all the brass fitting necessary as well as the taps. 3/8" NPT, 1/4" NPT, and 1/8" NPT taps and fittings are all pretty easily sourced. If I remember right, I believe 3/8" NPT is the size, and doesn't even require drilling the intake first. But double check that size...could be misremembering.
Hope that helps.