Hard brakes

Chuci · **Posted:** Mon Mar 15, 2021 7:27 pm

I’ve recently been having a problem where my brakes are really stiff. Going at 5 miles an hour I slam the brakes and instead of it stopping immediately it’s rolls and then stops. I’ve bled my brakes hoping it would help but it has not. This all started happening after removing my dash and the only thing I touch even closely related to the braking system was the brake light switch which I don’t think has anything to do with it. I checked for leaks before hand and nothing. Any idea what it could be? Thank you.

rankom · **Posted:** Mon Mar 15, 2021 9:20 pm

if your break rotors and pads are good, I would get somebody to do the break bleed test with a scan tool.

Billybob · **Posted:** Tue Mar 16, 2021 1:36 am

Jeeps with ABS need the brake light signal to operate!

Did you fit a new Brake Switch Assembly...the original assembly cannot be re-used once it has been removed! :shock:

I do not have ABS so cannot test it....don't even have Disks at the rear!

Do you have vacuum going to the Brake Booster...this is supplied by a small rubber pipe coming off the Vacuum Pump.

With the engine off press firmly on the brake pedal...should go down only a slight amount. Keep pressing the pedal and turn the engine over...the pedal should drop slightly under your foot if all is working well....must not go nearly all the way to the floor.

The 2006 KJ Service Manual states that only Dot 3 Brake fluid must be used...I use this for my 2002 Export CRD but I am sure that this is outdated and Dot 4 should be fine!

Otherwise could be the Master Cylinder!

Any Codes you can pull out that refer to the brakes? :wink:

Chuci · **Posted:** Tue Mar 16, 2021 4:33 pm

I did replace the brake light switch with a new one.

As for the line that connects to the brake booster which one is it?

I did have a code it was p0504 and I looked it up and it turned out to be a blown fuse which I replaced but the problem continues.

Sent from my iPhone using Tapatalk

Billybob · **Posted:** Wed Mar 17, 2021 6:19 am

There is a small rubber hose that comes from the Vacuum Pump, hits a T-junction somewhere to split the vacuum to the Brake Booster and to the cabin interior to drive the air-flaps. If there is no vacuum to the cabin then air will only blow out of the Demister Vents...not the side-vents or footwell.
I had this on my 2002 Export CRD where I only had demister vent airflow after the Agents knocked off the pipe somewhere after a Service.

I did not however have any brake issues so maybe there is a check-valve somewhere?

I do not know where this junction is but you should find a small pipe on the Brake Booster that should have vacuum on it when the engine is running...I will see if I can find it in the 2006 KJ manuals...I have never found it on my old CRD...maybe it is inside the Cluster somewhere!

WWDiesel · **Posted:** Wed Mar 17, 2021 1:12 pm

FYI: The "Tee" junction is over on the right side (Passenger side US) against the firewall where the vacuum tube goes through the firewall to the HVAC system.

When I replaced all my poor quality factory vacuum hoses and plastic tubing with silicone tubing, I relocated the "Tee" and check valve to over at the brake booster by adding a completely separate supply hose for just the HVAC and separate dedicated hose for just the turbo controls supply. (Picture 1)

Picture 2 shows the factory vacuum hose routing.

Factory Vacuum Hose Routing:

Chuci · **Posted:** Wed Mar 17, 2021 3:42 pm

Billybob wrote:

There is a small rubber hose that comes from the Vacuum Pump, hits a T-junction somewhere to split the vacuum to the Brake Booster and to the cabin interior to drive the air-flaps. If there is no vacuum to the cabin then air will only blow out of the Demister Vents...not the side-vents or footwell.
I had this on my 2002 Export CRD where I only had demister vent airflow after the Agents knocked off the pipe somewhere after a Service.

I did not however have any brake issues so maybe there is a check-valve somewhere?

I do not know where this junction is but you should find a small pipe on the Brake Booster that should have vacuum on it when the engine is running...I will see if I can find it in the 2006 KJ manuals...I have never found it on my old CRD...maybe it is inside the Cluster somewhere!

That is exactly what Is happening with my vents it’s only coming out the top and not any of the others.

Chuci · **Posted:** Wed Mar 17, 2021 3:58 pm

WWDiesel wrote:

FYI: The "Tee" junction is over on the right side (Passenger side US) against the firewall where the vacuum tube goes through the firewall to the HVAC system.

When I replaced all my poor quality factory vacuum hoses and plastic tubing with silicone tubing, I relocated the "Tee" and check valve to over at the brake booster by adding a completely separate supply hose for just the HVAC and separate dedicated hose for just the turbo controls supply. (Picture 1)

Picture 2 shows the factory vacuum hose routing.

Factory Vacuum Hose Routing:

So I checked that hoses that you guys told me and I was tracing one back behind the coolant reservoir and find out it’s not connected to anything. I’m guessing it’s not supposed to be like that.

WWDiesel · **Posted:** Wed Mar 17, 2021 9:33 pm

You are correct, it should be connected to the hose going through the firewall to the HVAC system in the dash.

Chuci · **Posted:** Wed Mar 17, 2021 9:55 pm

I’m assuming I’m removing the dash again.

Billybob · **Posted:** Thu Mar 18, 2021 1:39 am

At least you are an Expert now on removing the Dash! :lol:

Great pictures and explanation by WWDiesel!

Chuci · **Posted:** Fri Mar 19, 2021 5:11 am

Billybob wrote:

At least you are an Expert now on removing the Dash! :lol:

Great pictures and explanation by WWDiesel!

Not really sure I wanted to be an expert haha, it’s gets easier each time I do it atleast. Also Wwdiesel has been a great help in getting my car through all this

thesameguy · **Joined:** Sat Oct 01, 2016 8:24 pm **Posts:** 652

He's the best. LJ should start up a collection to buy him a beer. I know I'd chip in.

Chuci · **Posted:** Fri Mar 19, 2021 4:36 pm

thesameguy wrote:

He's the best. LJ should start up a collection to buy him a beer. I know I'd chip in.

A lot of people would pitch I bet.

WWDiesel · **Posted:** Fri Mar 19, 2021 9:26 pm

Thanks, and I do like Beer! :BANANA:

Chuci · **Posted:** Sat Mar 20, 2021 7:17 pm

I might just send it to a brake shop and they can tel me what’s wrong . Save me some time

Billybob · **Posted:** Sun Mar 21, 2021 7:21 am

Chuci wrote:

I might just send it to a brake shop and they can tel me what’s wrong . Save me some time

Why?

You definitely have your vacuum pipes not connected so that need sorting out! You will at least be getting vacuum to the Brake Booster and your interior vents.

If after fixing the above and your brakes are not working then take it to a shop!

If the Brake Shop has to remove and re-fit the Dash then they will definitely screw it up...that is not their line of expertise!

Chuci · **Posted:** Sun Mar 21, 2021 1:42 pm

I am starting to believe that it has to do something with no vacuum somewhere as something is up with my turbo too and other members are saying it could be that.

user113 · **Posted:** Tue Mar 23, 2021 9:19 pm

Yes, all symptoms seem to be pointing to a vacuum issue.

Also, to clarify a comment above regarcing DOT 4 brake fluid, my owner's manual states:

Quote:

Mopar(R) DOT 3 Brake Fluid, SAE J1703 should be used. If DOT 3, SAE
J1703 brake fluid is not available, then DOT 4 is acceptable. Use only recommended
brake fluids.

BTW, I love the vacuum hoses WWDiesel is using. If I can find them in yellow or green I will have to upgrade!

WWDiesel · **Posted:** Wed Mar 24, 2021 12:23 am

Chuci wrote:

I am starting to believe that it has to do something with no vacuum somewhere as something is up with my turbo too and other members are saying it could be that.

Plug off that :TEE" by shoving a small bolt into it that you showed in the picture you posted in your other post, that is where you are losing vacuum!

Hard brakes

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