Brake problems after 5 lug swap..

331 LX

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Guys, you all are my last resort on my problem here so I'm hoping I can find some help to shed some light.

In short... I did a 5 lug swap on my fox and am having issues with the front brakes. They don't seem to be working at all. There is still cross hatch on the new rotors and I have driven it a few times since the swap.

Here is the list of new parts..

-New PBR front calipers w/ pads
-New Maximum Motorsports SS lines
-New Master Cylinder
-New wheel cylinders in rear drums

My dad is an aircraft engineer / ex ford Mechanic from years ago so I have had some help from him but he works out of town and after this weekend I think he's done messing with it. haha

We have bled, bled and bled and bled the lines and no air or anything left in the lines. The pedal feel is shit, and literally 0 front brakes. Any ideas are welcome and very appreciative.
 

grd951

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Did you install a proportioning valve? Bias might be stuck in the rear.


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331 LX

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Did you install a proportioning valve? Bias might be stuck in the rear.


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I didn't. My dad called me on his way to his townhouse and said that was the only thing he could think of that the issue is. I didn't know that it was needed without doing the rear disc?
 
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grd951

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Yes it’s a fairly inexpensive unit. I purchased a wilwood from maximum Motorsports website. That should solve our problem sir, good luck! Also make sure you have the correct reservoir, I switched to a cobra reservoir and master when I did the cobra brake swap.


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331 LX

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Yes it’s a fairly inexpensive unit. I purchased a wilwood from maximum Motorsports website. That should solve our problem sir, good luck! Also make sure you have the correct reservoir, I switched to a cobra reservoir and master when I did the cobra brake swap.


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Thank man. I am going to order that Wilwood now. I got the Master Cylinder from Advance Auto and it came with a new reservoir.

I didn't get the 93 cobra reservoir because I was told it was only needed when doing the rear disc too. Is that false or should I order a cobra reservoir in place of the new factory one?

Thanks for your help, I genuinely appreciate it!
 

grd951

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I ended up going with the 03 master, booster, and res. I do have the rear disc setup so I would assume you’re ok. If you wanted to do the swap getting sn stuff out of s junk yard is the best way to go if you’re on a budget. That’s what I did. The brackets, axles and everything was only about 60 bucks from my local pick a part.


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331 LX

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I ended up going with the 03 master, booster, and res. I do have the rear disc setup so I would assume you’re ok. If you wanted to do the swap getting sn stuff out of s junk yard is the best way to go if you’re on a budget. That’s what I did. The brackets, axles and everything was only about 60 bucks from my local pick a part.


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Man, I'm spent after this. I'm really hoping the proportioning valve helps and maybe next year do all 4 disc.

Did you bleed all 4 corners...RR, LR, RF, then LF?

Oh yea... Several times, in that order. LOL
 

331 LX

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Sometimes air can gert stuck really well..... if the prop valves doesn't fix it, you may consider taking the car to a shop that can power bleed it.

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I may have to take it somewhere at this point. When bleeding them there was no air left in the system that we saw, and we bled them several times. Reading up on the Prop valve it says it only adjusts the rear brakes. I'm not sure how it will help since I have 0 pressure going to the front..
 

331 LX

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What master cylinder did you use?

Plus, have you physically checked the front calipers? If they are the 99-04 style PBR's, they have phenolic pistons and are known to have issues.

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I used a factory Master Cylinder for a 90 5.0.

I haven't physically checked the PBR's, I bought them at advance auto and tossed them on the car. I had a set previously and one was seized up so I said screw it and bought 2 new ones.
 

jfsram

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Both the 90 and the 93 Cobra master cylinder will work. I've tried both and all the Cobra one does is increase the piston size 1/16". It changes pedal feel slightly but neither one will cause problems.
 

ashleyroachclip

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I kept my 84 master , when i changed to pbr and 5 lug .
That was 10 or 15 years ago , and i have never hada problem.
I did need to adjust the push rod length slightly.
 

331 LX

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You can tell the calipers aren't doing their job up front. There is basically no wear at all on the rotors. I was busy over the holidays and it's cold as balls out right now so I haven't messed with it.
 

N A

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Any updates? I'm beginning to collect the parts for my 5 lug disc brakes upgrade. I completely forgot about the master cylinder and proportioning valve.
 

331 LX

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Any updates? I'm beginning to collect the parts for my 5 lug disc brakes upgrade. I completely forgot about the master cylinder and proportioning valve.
Not really any updates.

I took the car to get the tailpipes put on and for the shop to pressure bleed the lines and they couldn't find any issues. I know for certain this thing should be stopping better than it does though. I guess I'm going to get the proportioning valve to see if I can feed some more to the front and see what happens. That's the only other thing I can think of trying at the moment. Good luck with yours and let me know how it goes.

I'll post a pic with the new tails on below.

Edit- I know that you have to do the proportioning valve when doing rear disc's, I just didn't do them.

38707355720_10f37cb0ec_h.jpg


38707355350_189a9a19b7_h.jpg
 

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