Topic: Brake Booster

[jfrabat]

OK, so as some of you may remember, I have had problems with my brakes not biting right (for example, if I am driving at about 15 mph, I cannot lock the brakes no matter how hard I slam on the pedal).  Now I changed the master, because the pedal was also sinking as you held the brakes on, and I got some new calipers and put them on, but the problem persist.  I also put on a vacuum reservoir for the booster, as I thought it could also be a lack of vacuum (at that time, my defroster vents would come open when driving at highway speed, which means there was a shortage of vacuum; I fixed this with smaller vacuum reservoirs for the HVAC system). 

Anyway, the only piece that I think could possibly be is the brake booster (I also installed SS brake lines when I did the lift, so its not the lines expanding either).  So my questions are:

1. Where is the best place to find a good price on a brake booster?
2. Should I use a YJ brake booster, or should I look for another booster (in other words, should I take the opportunity to upgrade to something better)?
3. How difficult is it to swap a brake booster?  Is it something I can do myself?

Felipe

[Jeffy]

Adjust your rear drums and make sure you have no air in the lines?

Then maybe some softer compound pads and shoes.  High-mileage pads are high mileage for a reason, 

Next step would be;

TJ dual-diaphragm booster + E350 master + re-adjust rear brakes.

After that I'd go with;

WJ dual-pot front calipers and the matching discs...

[aw12345]

when the engine is idling spary brake cleaner or propane around the brake booster if the idle speed changes it leaks also check the check valve on the vacuum booster its the little plastic fitting that plugs into the brake booster and is attached to the vacuum line. To change it its easy disconnect the 2 nuts that hold the master cylinder and see if you can lay it aside without disconnecting the brake lines. Loosen the pedal connection under the dash you should also see 4 nuts around where the pedal connects on the firewall loosen those disconnect the check valve and it should pull right out piece of cake

[jfrabat]

Adjust your rear drums and make sure you have no air in the lines?

The rear brakes were shot (the drums were dead and the entire system was replaced by a crappy mechanic, so I had to replace the whole thing again; because it is the brakes we are talking about, I had it done by a reputable shop).  The lines have been bled about 5 or 6 times already, so no air there.

Then maybe some softer compound pads and shoes.  High-mileage pads are high mileage for a reason, 

I thought it was the pads, but a couple of times, early in the morning, the brakes have worked properly, and then the jeep's brakes feel fine.  But that ussually only works for about 2 or 3 miles and then is back the the ussual, so it is not the pads (besides, it worked just like that before I changed the pads to the new pads I now have on).

Next step would be;

TJ dual-diaphragm booster + E350 master + re-adjust rear brakes.

After that I'd go with;

WJ dual-pot front calipers and the matching discs...

So I have to change the master as well for this...  huh, I guess I'll just go stock then (I have already thrown too much money at this particular problem!).

when the engine is idling spary brake cleaner or propane around the brake booster if the idle speed changes it leaks also check the check valve on the vacuum booster its the little plastic fitting that plugs into the brake booster and is attached to the vacuum line. To change it its easy disconnect the 2 nuts that hold the master cylinder and see if you can lay it aside without disconnecting the brake lines. Loosen the pedal connection under the dash you should also see 4 nuts around where the pedal connects on the firewall loosen those disconnect the check valve and it should pull right out piece of cake

I dont think it is a leak, because when I disconnect the vacuum reservoir, I can hear a TON of air rushing in, meaning that the is enough vacuum in the system, but I will check anyway.  If it's not it, I guess I'll spend the $140 and throw a new one in there...

[oldjeep]

Might also want to check the SS lines.  People seem to be under the impression that they are an improvement over stock.  Rather than a thick rubber line you get a little skinny nylon line packed inside a piece of rubber and some stainless.

[smashcoast]

What brake pads are the best for a 97TJ with 31x10.50 if it matters?

[Jeffy]

So I have to change the master as well for this...  huh, I guess I'll just go stock then (I have already thrown too much money at this particular problem!).

You can swap in a complete TJ master and booster for cheap from salvage.  Doing the E350 master can be installed on the stock booster and is dirt cheap as a rebuilt.

[aw12345]

Now that I think of it the problem could be much simpler, sometimes vacuum hoses collapse internally, you might want to check the hose to the brake booster it could be severely restricted and that will cause the problem you describe. Provided the pedal is hard and at the proper height, but it just doesn't want to stop very well.
Does the pedal get harder and come up a bit after you hit the brakes a couple of times? Normally after shutting of the engine you should have atleast 2 to 3 brake applications with brake assist befor the pedal gets hard with no assist

[jfrabat]

The lines I already replaced, so it is not that.  I also tested the vacuum by disconnecting the valve at the booster side with the engine off (keep in mind I have a rather large vacuum reservoir, so there is still vacuum in the system) and I could clearly hear the rush of air as I disconnected it, so I dont think it is that...  I guess I'll get a new booster and just swap it in.

[jfrabat]

Adjust your rear drums and make sure you have no air in the lines?

Then maybe some softer compound pads and shoes.  High-mileage pads are high mileage for a reason, 

Next step would be;

TJ dual-diaphragm booster + E350 master + re-adjust rear brakes.

After that I'd go with;

WJ dual-pot front calipers and the matching discs...

Jeffy,

What brake pads would you recommend?  I am thinking about getting the Hawk LTS, but dont know if that would be the best choice...  I do have some high mileage pads there that are fairly new, but the Jeep is still not stopping (I already changed the booster, which means that I have already replaced booster, master, calipers, rear drums, rear shoes and pads).   I want to try a set of soft pads that really bite before changing the booster and master again to higher sized ones...  So advice is REALLY appreciated!

[Jeffy]

Jeffy,

What brake pads would you recommend?  I am thinking about getting the Hawk LTS, but dont know if that would be the best choice...  I do have some high mileage pads there that are fairly new, but the Jeep is still not stopping (I already changed the booster, which means that I have already replaced booster, master, calipers, rear drums, rear shoes and pads).   I want to try a set of soft pads that really bite before changing the booster and master again to higher sized ones...  So advice is REALLY appreciated!

For me I'd probably go with some Hawk's.  I'm not sure which ones though.  I'm still on my stock pads!   

Swapping out the master is cheap though.  Get a rebuild and it's under $20.

[jfrabat]

I guess I'll get the Hawk LTS (according to Hawk, these are the ones that have the best stopping power when cold, and since the Jeep is light, they will offer the most bite).  As for the master, if I change the master I also need to change the booster to feel the improvement, right?

[Jeffy]

As for the master, if I change the master I also need to change the booster to feel the improvement, right?

Nope.  Although the best thing would be to swap over to a TJ booster while you're at it.

[jfrabat]

Nope.  Although the best thing would be to swap over to a TJ booster while you're at it.

So what year of E350 would work?

[Jeffy]

This is what I'm going to be using when I get around to doing it.

1986 FORD E-350 ECONOLINE Engine: V8 5.8 Liter