# Brake lines for mkIV rear calipers on a mkIII with drums



## HilF (Jan 10, 2004)

hokay, so i have everything i need to convert my rear drums on my mkIII to rear disc.
i want to know what/where to get braided brake lines that go from the drum hardline to the mkIV calipers.
should be a female on one side and a banjo on the other.








sell them with their drum to disc conversion, but i want braided lines.
cheers!


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## flieger (Jun 28, 2000)

yea...good luck....short of having someone custom make them for you...I continue to get the run around from ESC about this and a few other things...hence the reason I still have drums on the back


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## Racer_X (Jul 14, 2002)

*Re: Brake lines for mkIV rear calipers on a mkIII with drums (white_r!ce)*

Just use the rubber lines. They are more than adequate, and if you keep them fresh (replace every 4 to 5 year, every other brake flush), they will be fine. Also, for anyone upgrading from the A3 rear calipers (hose at the bottom) to the A4(Golf/Jetta/New Beetle) aluminum calipers, those lines will be a little short. You can use the lines for a 2002 Audi A4, and those will be long enough to loop from the hard line below the trailing arm to the banjo fitting at the top of the caliper. Unless you shorten the hard line and reflare it, the Audi A4 lines are too long if you are swapping from drums and keep the lines above the trailing arm.
If your car has ABS, you'll be good to go. You will notice a lot of ABS activity, though, because the rear wheels will be locking up early and the ABS will have to correct that.
If your car lacks ABS, I'd seriously consider the A3 Golf/Jetta calipers. The later aluminum calipers have much larger pistons, and will seriously overbias the brakes to the rear. Unless you really know how to adjust the proportioning valves or load sensing brake pressure regulator, you'll have a fairly dangerous setup where the rear wheels will lock up first (and very early) when you apply the brakes hard. I'm not sure if there's enough adjustment in the stock setup for the regulator on an A3 (or A2) cars to get the rear pressure down low enough to correct that.


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## punkassjim (Sep 22, 2002)

*Re: Brake lines for mkIV rear calipers on a mkIII with drums (Racer_X)*


_Quote, originally posted by *Racer_X* »_If your car has ABS, you'll be good to go. You will notice a lot of ABS activity, though, because the rear wheels will be locking up early and the ABS will have to correct that.
If your car lacks ABS, I'd seriously consider the A3 Golf/Jetta calipers. The later aluminum calipers have much larger pistons, and will seriously overbias the brakes to the rear. Unless you really know how to adjust the proportioning valves or load sensing brake pressure regulator, you'll have a fairly dangerous setup where the rear wheels will lock up first (and very early) when you apply the brakes hard. I'm not sure if there's enough adjustment in the stock setup for the regulator on an A3 (or A2) cars to get the rear pressure down low enough to correct that. 

I have a trick question for you: I have a mk3 with mk4 calipers all around, a mk4 brake booster/MC unit, and mk4 ABS controller. I also have mk4 braided hoses up front, and mk4 rubber hoses in the rear. My question is, do you think I'll have an overbias to the rear? I didn't notice any proportioning valves on either my car or my donor car...but I could have overlooked. Anyway, AFAIK, all braking components on my car are mk4 except the hard brake lines and the rotors themselves. Do you think I'll have premature lockup in the rear? (uh...heh...heh-heh







)


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## fluxburn (Sep 23, 2002)

*Re: Brake lines for mkIV rear calipers on a mkIII with drums (punkassjim)*

I was interested in upgrading my brakes for my mk3 2.0 because they suck. But this is rather disturbing you telling of the rear brakes locking up even worse then they already do with the drum brakes. What is the best way to have a balanced brake system on these cars lol. Should you just swap a g-60 setup or from a vr-6?


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## Racer_X (Jul 14, 2002)

*Re: Brake lines for mkIV rear calipers on a mkIII with drums (punkassjim)*


_Quote, originally posted by *punkassjim* »_I have a trick question for you: I have a mk3 with mk4 calipers all around, a mk4 brake booster/MC unit, and mk4 ABS controller. I also have mk4 braided hoses up front, and mk4 rubber hoses in the rear. My question is, do you think I'll have an overbias to the rear?

If you disable the ABS, your brakes will be overbiased to the rear. With the ABS functioning properly, the ABS will modulate the rear pressure to keep the rear brakes from locking up even though the system is imbalanced. You will just notice the ABS kicking in at less than absolute full braking.
Actually, with ABS, the engineers leave the braking system imbalanced by design. If the braking system is perfectly balanced (or nearly so), then it would be possible to lock all 4 wheels at exactly the same time, and the ABS wouldn't be able to tell if you you just stopped, or if you are skidding along with all 4 wheels locked. With an imbalanced system like the VW's with ABS have, it's not possible (well, almost not possible) to lock all 4 wheels at the same time.

_Quote, originally posted by *punkassjim* »_I didn't notice any proportioning valves on either my car or my donor car...but I could have overlooked. Anyway, AFAIK, all braking components on my car are mk4 except the hard brake lines and the rotors themselves. Do you think I'll have premature lockup in the rear? (uh...heh...heh-heh







)

You'll have ABS modulating the rear brakes to perform the function similar to the proportioning valve in non-ABS cars. In theory, the ABS will do a better job than the load sensing regulator on the non-ABS cars. Theoretically, the ABS will always be getting maximum braking force from the rear brakes.
If you pull the ABS fuse, or the ABS is disabled for some other reason, you'll experience premature lockup in the rear, and a braking system that's seriously overbiased to the rear.


_Quote, originally posted by *fluxburn* »_I was interested in upgrading my brakes for my mk3 2.0 because they suck. 


What brakes are on your car now? And are you sure that they are working properly? 
IMO, with proper pad selection, 9.4" vented fronts with rear drums are more than adequate for spirited driving and track driving (even racing provided you use race compound pads) for any VW under 2500 pounds that never exceeds 130mph. 
10.1" fronts with 200mm rear drums or 8.9" rear discs (A2/A3 rear discs) are good for anything up to about 3000 pounds that never exceeds 130mph or anything up to 2500 pounds that never exceeds 145-150mph (if you go this fast, rear discs are really a good idea). 
Those estimates assume a few basic things. Good pad selection is a must. Having reasonable wheels is also assumed. For spirited street driving, alloys with a reasonably open spoke pattern are needed. For track driving at the upper speed ranges, more open spoke patterns and even some air ducting may be needed to keep brake temperatures reasonable.
Putting bigger brakes on than you need is packing on extra rotating weight (slowing down your accelleration) and packing on a lot of extra unsprung weight (hurting handling). 
Also, in my experience, 75-80% of VW's with drum brakes that are over 8 years old have serious problems with the rear brakes. In those cases, fixing the brakes would give you as much "stopping power" as "upgrading" to rear discs. Unfortunately, it's getting very difficult to find people who know how to properly maintain and repair drum brakes, so changing to rear discs if you have drums is one way to get something most mechanics understand how to repair.

_Quote, originally posted by *fluxburn* »_But this is rather disturbing you telling of the rear brakes locking up even worse then they already do with the drum brakes. What is the best way to have a balanced brake system on these cars lol. Should you just swap a g-60 setup or from a vr-6?

The best way to have a balanced system is to maintain the brakes and the braking system properly. Also, know how the load sensing proportioning valve works, and adjust it properly when making suspension modifications.
As I mentioned, the cars with ABS will be overbiased toward the rear by design. Keep the ABS maintained on these cars and the ABS will modulate the rear brakes for you, preventing them from locking the rear wheels.
On cars without ABS, if you are having problems with the rears locking up, either the pressure regulator on your rear brakes is malfunctioning, or it is badly misadjusted. If you lower your car, you *must* adjust the pressure regulator to compensate for the change in ride height. Otherwise, the car thinks you put so much stuff in the back that you weighted it down for the entire drop. It will then apply much more rear brakes because it thinks there is real weight back there to keep the wheels gripping. 
If you lower the car, but stay near stock with the spring rates, you can just release some of the tension on the regulator spring. Measure the distance between the posts the spring mounts to before you change the suspension (with the car on the ground, not with it jacked up or on jack stands). After the suspension upgrade, reset the spring post on the suspension for the same distance as when you had the stock suspension installed. 
If you significantly stiffen the rear springs, you might also have to modify or fabricate a new lever arm on the suspension. The stiffer your springs are, the farther from the trailing arm pivot point the spring post needs to be. Some testing with the car unloaded, and then loaded with some kind of ballast (200-300 pounds of kitty litter works good) will help you set the regulator for optimum braking. Do this testing on a big empty parking lot, or somewhere where you can be safe and not endanger yourself or others with your tests. Also, make sure the "ballast" is secure and can't come flying forward through the cabin.


_Modified by Racer_X at 1:29 PM 4-27-2004_


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## fluxburn (Sep 23, 2002)

*Re: Brake lines for mkIV rear calipers on a mkIII with drums (Racer_X)*

Well it seems my brakes have been properly maintained but I will adjust them myself after reading what you have stated above. I just got some 17 inch wheels that have way better tires and noticed that I can brake way better already. I really don't think my braking is adequate though. I depress my brake pedal and just want more stopping power plain and simple. I do not have abs... maybe that is the probelm. Yet when I drive a bmw you can really slam on the breaks and not even feel the abs coming on. In my car you slam the pedal to hard and the rears just lock up or the fronts lock up. Its either or. The really annoying thing is that if you slam on the brakes on the freeway, it takes it to all one tire really. Ie I was going 50mph and had to stop immdetiatly and it ate my right front tire pretty bad. I guess that is normal depending on the cars placement and gravity to possibly be absorbed completely by one tire.
I was thinking about upgrading my brakes to larger ones, but first I will try your adjustments. If that isn't to my satifsfaction, maybe I will look into an abs module.


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## punkassjim (Sep 22, 2002)

*Re: Brake lines for mkIV rear calipers on a mkIII with drums (Racer_X)*


_Quote, originally posted by *Racer_X* »_If you disable the ABS, your brakes will be overbiased to the rear. With the ABS functioning properly, the ABS will modulate the rear pressure to keep the rear brakes from locking up even though the system is imbalanced. You will just notice the ABS kicking in at less than absolute full braking.
Actually, with ABS, the engineers leave the braking system imbalanced by design. If the braking system is perfectly balanced (or nearly so), then it would be possible to lock all 4 wheels at exactly the same time, and the ABS wouldn't be able to tell if you you just stopped, or if you are skidding along with all 4 wheels locked. With an imbalanced system like the VW's with ABS have, it's not possible (well, almost not possible) to lock all 4 wheels at the same time.
You'll have ABS modulating the rear brakes to perform the function similar to the proportioning valve in non-ABS cars. In theory, the ABS will do a better job than the load sensing regulator on the non-ABS cars. Theoretically, the ABS will always be getting maximum braking force from the rear brakes.
If you pull the ABS fuse, or the ABS is disabled for some other reason, you'll experience premature lockup in the rear, and a braking system that's seriously overbiased to the rear.

Excellent information, thank you! I figured when ABS is on the fritz I'll have proportioning issues, but I also was under the assumption that as it stands now, I haven't got any bias issues. Seems to be the case. At times, I get some ABS kick-in when cornering hard, but usually nothing. Also, the ASR seems to be working fine too. It's just good to know the ABS unit does the proportioning for me, since I was scared I might have missed a proportioning valve.
I wonder if I went ahead and, for mostly cosmetic reasons, upgraded my rear rotors to 11" eurospec units (using my stock mk4 calipers), I would experience more frequent ABS intervention. My eventual plan is to have 13" front rotors and 11" rears, all with stock calipers.


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## Racer_X (Jul 14, 2002)

*Re: Brake lines for mkIV rear calipers on a mkIII with drums (fluxburn)*


_Quote, originally posted by *fluxburn* »_Well it seems my brakes have been properly maintained but I will adjust them myself after reading what you have stated above. I just got some 17 inch wheels that have way better tires and noticed that I can brake way better already. I really don't think my braking is adequate though. I depress my brake pedal and just want more stopping power plain and simple. I do not have abs... maybe that is the probelm. Yet when I drive a bmw you can really slam on the breaks and not even feel the abs coming on. In my car you slam the pedal to hard and the rears just lock up or the fronts lock up. Its either or. The really annoying thing is that if you slam on the brakes on the freeway, it takes it to all one tire really. Ie I was going 50mph and had to stop immdetiatly and it ate my right front tire pretty bad. I guess that is normal depending on the cars placement and gravity to possibly be absorbed completely by one tire.

It sounds like you need a bit of driver education/training, and a lot of practice time. I'll try to give you a few tips here. These tips are for drivers without ABS. I'll comment a bit at the end about how ABS changes things. You say yours doesn't have ABS.
First, braking is all about weight transfer. So is handling. As you apply the brakes, weight transfers off the rear wheels and onto the front wheels. The front of the car goes down a bit, and the back of the car comes up. That's why front brakes do more of the work. The front wheels have more grip (from greater downforce from the weight of the car transfering to the front wheels). 
This is important. If you jam on the brakes really quickly, you will most likely lock the front wheels. That's because your brakes are applying full force, trying to stop the wheel, but the suspension hasn't had time to move and all of the weight that would normally transfer to the front hasn't settled on the front wheels yet. So, without ABS, it's important to squeeze on the brakes. You can be firm, and fairly quick in an emergency, but don't push the pedal faster than the car rocks forward on the suspension. If you slow down your pedal movement just a little bit, you'll be able to apply a lot more brakes without locking up the front wheels. If you lock the front wheels with the initial stomp on the pedal, you'll take a lot farther to stop.
The second weight transfer issue has to do with turning. Weight transfers from the inside wheels to the outside wheels when you turn. When you are turning to the right, your right wheels have less weight on them (and less grip as a result), and your left wheels have more weight on them (and more grip as a result). Without ABS, you will be limited by the wheel with the lightest load (the inside wheel). It's a good idea to straighten the steering wheel some when you have to brake hard. A defensive driver will hug the inside edge of his lane going around a turn, that way, if he has to get hard on the brakes, he can straighten the wheel some and have some distance where he can brake more effectively without driving out of his lane. I do this all the time. It's second nature to me that if I have a surprise that requires braking, and I'm in a turn, I straighten the wheel as I push the brake pedal. The harder I brake, the more I straighten the wheel. 
Now, if you have ABS, you can still drive the car like I was describing. You'll be making the ABS controllers job a little easier, and you won't feel the ABS taking control of the car as often. But, if you have an emergency, and your car has ABS, you can also just jam the brake pedal down as fast and as hard as you can and let the computer figure out how to get the car slowed down. Still, if you have a lot of steering input (you're in a sharp turn), the ABS can have to release the brakes to a surprising degree to keep the wheels from locking, and the stopping distance can be a lot longer than you think. ABS is not magic. It can't make traction where there isn't any, and it's limited by the weight and grip at each wheel. 

_Quote, originally posted by *fluxburn* »_Well iI was thinking about upgrading my brakes to larger ones, but first I will try your adjustments. If that isn't to my satifsfaction, maybe I will look into an abs module.

Every watercooled VW I've ever driven (and I've driven a lot of them) has had excellent brakes. With proper pad selection, you will not have any problem with fade or lack of braking force. Proper pad selection is the key. 
Try some good pads in your stock brakes before you go to larger brakes. Ferodo DS-2500 (or DS-2000 if you don't drive as hard and have limited funds), Hawk HP+ (or HPS if you don't drive as hard, or for the earlier, lighter cars), or Porterfield R4-S are all excellent pads. They have lots more grip than the stock brake pads from VW, meaning you get a lot more braking force from the same pressure on the pedal. 
Switching from the stock pads (or parst store cheapies, or even Mintex Red Box) to the Ferodo DS-2000 will give you as much increase in braking force as changing from the stock (11 inch) rotor to about a 15 inch rotor with the stock calipers and pads (if that was even available). Going to DS-2500 is an even bigger increase in braking force and fade resistance.
Also, don't forget that your tires are probably the biggest limit on how quickly your car can stop. Once you can lock all 4 wheels under all driving conditions, more brakes won't stop the car any quicker. At that point, the only thing that will stop the car quicker is grippier tires. 

_Quote, originally posted by *punkassjim* »_It's just good to know the ABS unit does the proportioning for me, since I was scared I might have missed a proportioning valve.

Nope, no prop valve in the ABS cars. The ABS does perform a similar function in a slightly different way.

_Quote, originally posted by *punkassjim* »_I wonder if I went ahead and, for mostly cosmetic reasons, upgraded my rear rotors to 11" eurospec units (using my stock mk4 calipers), I would experience more frequent ABS intervention. My eventual plan is to have 13" front rotors and 11" rears, all with stock calipers.

Going bigger at the rear without a similar increase at the front would probably throw more imbalance into the system, resulting in more frequent ABS intervention (as you put it). 
See my notes above about pads and tires and brake upgrades. It sounds like you already understand that big brake upgrades are mostly cosmetic on these cars (and can hurt handling and acceleration to a slight degree).


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## fluxburn (Sep 23, 2002)

*Re: Brake lines for mkIV rear calipers on a mkIII with drums (Racer_X)*

Ok thanks a lot man. The last time I got my brakes done was at a shop with mintex red's. I thought they were excellent, but I guess thier are much better as you describe above. I will take your advice and press on the brakes slightly less hard and improve my braking skills in a parking lot soon. 
So your saying I should just totally keep my existing brake setup and learn how to drive it. I will take your advice.


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## o2bad455 (Aug 22, 2003)

*Re: Brake lines for mkIV rear calipers on a mkIII with drums (Racer_X)*


_Quote, originally posted by *Racer_X* »_Also, for anyone upgrading from the A3 rear calipers (hose at the bottom) to the A4(Golf/Jetta/New Beetle) aluminum calipers, those lines will be a little short. You can use the lines for a 2002 Audi A4, and those will be long enough to loop from the hard line below the trailing arm to the banjo fitting at the top of the caliper. 

I'm confused. A3 seems to have hydraulic brake hose on top. Did you mean to say A1/A2 rather than A3 above? If so, which stock lines work for A4 rear calipers on an A3 car that did originally have rear disks?


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## o2bad455 (Aug 22, 2003)

For Mk3 disk to Mk4 caliper conversion, the Mk4 calipers take a larger diameter hose fitting, probably because aluminum threads of the same size would be easier to strip than steel. The banjo isn't necessary, if you can find the right fitting on a hose. I've heard that either Passat B4 or Cabrio Mk3.5 rear lines might work, but no one has bothered to confirm after figuring it out. I know a few places offer custom lines (GAP, ECS, etc.), but I refuse to do the swap unless I can use stock lines (for speedy replacement if needed). So, can anyone confirm a stock line that fits, or better yet, a simple thread adapter to use the Mk4 caliper with the Mk3 line?


_Modified by o2bad455 at 8:52 PM 4-8-2009_


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