Replacing Brake System

Nishan.dj · May 23, 2011

Hi friends,

According to my knowledge originally 4DR5 Jeeps come with a single master cylinder with a relevant brake servo and from the the cylinder the oil goes to all the 4 wheels. I was thinking about replacing the unit with a pump that has 4 master cylinders which can serve each wheel separately. I just thought that It would make the system independent in each and every wheel and also powerful. So if you have any idea about it or have done it before please add a reply. I think the Brake Servo also has to be replaced then. Please add a reply if you have any information about this? Thanks a lot in advance.

The Don · May 23, 2011

Nishan, does your current brake system have any problems ? I'm trying to understand why you have decided on such an upgrade. I mean there are a number of ways upgrading the brakes. Switching to disc brakes, having bigger discs, upgrading to a bigger master cylinder etc etc. But as with all such upgrades, the upgrade should fit the reason behind the upgrade, hence my question.

Nishan.dj · May 24, 2011

On 5/23/2011 at 12:49 PM, The Don said:

Nishan, does your current brake system have any problems ? I'm trying to understand why you have decided on such an upgrade. I mean there are a number of ways upgrading the brakes. Switching to disc brakes, having bigger discs, upgrading to a bigger master cylinder etc etc. But as with all such upgrades, the upgrade should fit the reason behind the upgrade, hence my question.

Hi Don,

Thanks for the reply. The brake is not enough for sudden stop and also having some issues with adjusting them with the wheels which is sometimes little hard because the each has its own limit of adjusting. However I just though that it would be more controllable and also secured to use that kind of cylinder that can serve each wheel separately. Anyway if this is a stupid idea let me know it as well

Upgrading to disc brakes will cost more than doing the above work I guess and I have no idea about upgrading to bigger master cylinder and I think it also a good option. So what would be the best thing to do to get more control when braking. Thanks again.

Edited May 24, 2011 by Nishan.dj

The Don · May 24, 2011

On 5/24/2011 at 3:26 AM, Nishan.dj said:

Hi Don,

Thanks for the reply. The brake is not enough for sudden stop and also having some issues with adjusting them with the wheels which is sometimes little hard because the each has its own limit of adjusting. However I just though that it would be more controllable and also secured to use that kind of cylinder that can serve each wheel separately. Anyway if this is a stupid idea let me know it as well

Upgrading to disc brakes will cost more than doing the above work I guess and I have no idea about upgrading to bigger master cylinder and I think it also a good option. So what would be the best thing to do to get more control when braking. Thanks again.

Hi Nishan, I've not come across brake systems which have a separate cylinder for each wheel yet (they might exist but I just haven't come across them)and such a system would be quite complicated as well as there is the small issue of balancing the brakes between the wheels. Too much brake force to one side and the vehicle will twitch under braking. I have seen systems where the front and back are served separately and can be adjusted separately.

I think the first thing to figure out is that if the problem you are facing an inherent issue in your model. If it isn't then simply reconditioning your brake system would resolve the issue. Your Jeep is quite old now so your brake system might need an overhaul to function as it once did many years ago. First find out the problem and then look at solutions. My personal view is modifying the brake system should be the very last option as we don't know what other problems that would bring about.

Watchman · May 24, 2011

As a pet project my dad and i did a brake upgrade on our 4DR5 too. We gave it a new servo (originally from a hyundai vas as i remember). It really doesnt require 4 master cylinders. But the 4 lines are drawn individually from the master, rather than one line split into 4.

Yours is probably a single line split into 4. The loss of effectiveness could be due to a oil/pressure leak in one/some of the wheels, and the pressure equalizing at all 4 wheels. Fix that and you should have your breaks back.

In our case the the 4 individual lines gives a whole new issue. Now if there's a leak in one wheel, the jeep will pull in the opposite direction direction (worse if its the front). That happens to ours if/when there's a leak somewhere. But I personally prefer this over loosing effectives on all wheels cos after a few strokes of the break you instinctively steer in the opposite direction of the pull when breaking.

Edited May 24, 2011 by Watchman

Nishan.dj · May 24, 2011

On 5/24/2011 at 9:53 AM, Watchman said:

As a pet project my dad and i did a brake upgrade on our 4DR5 too. We gave it a new servo (originally from a hyundai vas as i remember). It really doesnt require 4 master cylinders. But the 4 lines are drawn individually from the master, rather than one line split into 4. Yours is probably the same. Ur probably getting a loss of effectiveness due to a oil/pressure leak in one/some of the wheels. Fix that and you should be good to go. But this will mean if you still havent fixed that leak you jeep will pull in that direction. That happens to ours if/when there's a leak somewhere.

Hi Watchmen,

This is interesting. All 4 lines are drawn individually from the master is a very good solution. In my jeep there is no oil leaks but as an option I was thinking to have little bit better effectiveness on brakes. I think you have replaced not only the servo but also the master cylinder as well and can you suggest me a good one that can drawn lines individually as you did. And what is the servo you have given? Thanks a lot.

Edited May 24, 2011 by Nishan.dj

Watchman · May 24, 2011

On 5/24/2011 at 10:06 AM, Nishan.dj said:

Hi Watchmen,

This is interesting. All 4 lines are drawn individually from the master is a very good solution. In my jeep there is no oil leaks but as an option I was thinking to have little bit better effectiveness on brakes. I think you have replaced not only the servo but also the master cylinder as well and can you suggest me a good one that can drawn lines individually as you did. And what is the servo you have given? Thanks a lot.

This was done 5-6 years ago, and like i said i THINK it was form a hyundai van (but basically bought from a scrap yard in P.watta).. But anything from a big van or any other vehicle of similar weight should do i guess.

I'm not in the country so i cant send u a photo of it. Basically the metal manifold kinda thing has to have 4 lines coming out of it. Kinda like what it would look like if it was a ABS unit, but with obviously different internals.

Janith Seneviratne · May 24, 2011

nishan did you checked your brake liners, how they are worn,replace the liners and balance the brake i think you have a two line master cylinder and 4dr5's original brake lines so each line get separated to two at the 'T' connector mounted to the diff 1st try balancing the brake im sure sum of your liners r worn of unequally cz of nt balancing properly if theres no oil leaks n btw check the spring tensions in side the brake drum,

so u replaced ur Booster?

Nishan.dj · May 25, 2011

On 5/24/2011 at 1:59 PM, Janith Seneviratne said:

nishan did you checked your brake liners, how they are worn,replace the liners and balance the brake i think you have a two line master cylinder and 4dr5's original brake lines so each line get separated to two at the 'T' connector mounted to the diff 1st try balancing the brake im sure sum of your liners r worn of unequally cz of nt balancing properly if theres no oil leaks n btw check the spring tensions in side the brake drum,

so u replaced ur Booster?

Hi Janith..

The brake lines are warn as you said.

On 5/24/2011 at 1:59 PM, Janith Seneviratne said:
im sure sum of your liners r worn of unequally

I actually have not noticed this and will check again. I think as you said if those are unequally warn the brake would be unbalanced. The booster have replaced some time back before I buy her. Thanks.

Nishan.dj · May 25, 2011

On 5/24/2011 at 1:59 PM, Janith Seneviratne said:

nishan did you checked your brake liners, how they are worn,replace the liners and balance the brake i think you have a two line master cylinder and 4dr5's original brake lines so each line get separated to two at the 'T' connector mounted to the diff 1st try balancing the brake im sure sum of your liners r worn of unequally cz of nt balancing properly if theres no oil leaks n btw check the spring tensions in side the brake drum,

so u replaced ur Booster?

Hi Janith..

The brake lines are warn as you said.

On 5/24/2011 at 1:59 PM, Janith Seneviratne said:
im sure sum of your liners r worn of unequally

I actually have not noticed this and will check again. I think as you said if those are unequally warn the brake would be unbalanced. The booster have replaced some time back before I buy her. Thanks.

Shehan_WCC · May 26, 2011

If your liners are worn it will obviously be unequal braking,check the master cylinder brake washers,or you can modify the system with a tandem master cylinder and then the brake lines could be split into 2 (X split).Depends on the brakes and the master cylinder you use ,the braking system is a major system so it could get pretty complicated.

Janith Seneviratne · May 28, 2011

nishan, does your pressure differentiation switch work? if not fix it(just disassemble it,clean it with WD40, change the 'O' rings re assemble), then you could knw whether to change the master cylinder or to balance the brake