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View Full Version : Brake issues in my v8 ranger


ran94ger
05-03-2010, 06:08 PM
Hey everyone.
Ever since i did the v8 conversion my brakes have been soft and the pedal goes to the floor when truck is running and when the truck is not running and i pump them up they pump up like normal and are hard, but like i said when truck is on its almost like nothing is there. I have bled the brakes so many times, and have had my mechanic pressure bleed them with a special tool. I put the b303 cam in the truck, don't think that would be why. I put a brake line lock kit in, don't think that matters. all new braided flex lines, calipers, rotors, drums, wheel cylinders, and master cylinder. All that is left is the power booster. I don't get it, please help!

RAT Ranger
05-03-2010, 07:55 PM
No offense intended..............when your bleedin them, your doin it with the truck off, right?

If they get hard when bled with truck not runnin, then they get soft when started, sounds like either the booster has gone south or you don't have enough vacuum for the booster, which could be fixed with a vacuum canister.

FFT:)

TheStig
05-03-2010, 08:23 PM
^^^ ditto

sounds like a vacuum problem

281ranger
05-05-2010, 06:46 PM
Check where your brake lines are routed. If they are against the exhaust (or anything that gets hot enough) it causes the brake fluid to "boil" creating gas bubbles, much like having air in the lines.

A bad booster or not enough vacuum will make the pedal harder to depress, not easier.

RAT Ranger
05-05-2010, 07:34 PM
Check where your brake lines are routed. If they are against the exhaust (or anything that gets hot enough) it causes the brake fluid to "boil" creating gas bubbles, much like having air in the lines.
A bad booster or not enough vacuum will make the pedal harder to depress, not easier.
====================================
:adore:GOOD INFO, in all my years of toyin with vehicles, I've never heard/been told that!!!

As the sayin goes: "You learn somethin new every day!"

Psychopete
05-06-2010, 01:42 PM
I have a B303 in my Ranger and my stock brake system works fine..

allnpt0
05-09-2010, 01:46 PM
If you have drums in the rear, try adjusting them a little tighter. Just where the shoes start to touch the drum.

ran94ger
05-10-2010, 06:56 PM
Thanks for all the advice everyone. I bleed the brakes with the engine off. I've heard of the boiling fluid before, i had that problem with my car, don't think lines are close to headers or exhaust. Too much vacuum i feel would cause the brakes to be too soft. If booster goes bad, i think the pedal would be too hard. I have the rear brakes adjusted with slight drag on the drums. What about the line locks in the front? I might take the line locker off just to rule that out. I was even thinking too much vacuum making it too soft. Something is not right because the truck doesn't stop as good as it did with the 2.3L. obviously the V8 is heaver but i read that it was only 150lbs more, like a passenger. and thats not much.

ran94ger
05-10-2010, 07:00 PM
I don't think there is any moisture in the lines because when the truck is off and i pump them and bleed them, they get rock hard like any other car i've done. and as soon as engine is on they go to the floor.

Airtruksrus
05-26-2010, 03:52 PM
ever get the problem solved? Had the same problem and did a complete brake job with no luck, turns out there was a vacuum leak at the booster. Reseated the rubber grommet going into the booster and the brakes came back. They tend to get soft if you repeatedly step on them and reduce the vacuum in the manifold but it should bring the vacuum back up by letting off the brakes within 5 seconds. The other problem could be your booster is bad. Find if you have a leak elsewhere in the system.

ran94ger
07-25-2010, 04:50 PM
no never figured it out. p.s. sorry to respond as late and thanks for trying to help. the thing is, i don,t have any vacuum leak, when i pull out the hose even when truck is off for a while it still get lets off vacuum, so its holding vacuum good. i would think if the booster is bad than it would be really hard or stiff. i did turn up the idol a few hundred rpm,s to what it should be, and it helped a very small bit, i think, but still not right. it was great before the v8 swap and now crap. it is worse at idol than driving down the road i've noticed.

Airtruksrus
07-26-2010, 08:27 PM
Guess if youv'e checked the vacuum for the booster, a faulty booster such as a hole in the diaphram would prevent the brakes from grabbing, foot goes to the floor and you would lose vacuum. The only other idea that affected mine was water in the calipers(rusted) but not so in your case since you've had them bled several times. Don't know of what else except for anything that keeps the hydraulic pressure from getting to the brake actuators. Good luck

ran94ger
08-02-2010, 02:21 PM
Thanks for the help! Maybe I will replace the brake booster some time.

wesvo
08-03-2010, 09:38 PM
try changing you master cilinder it might be week

ran94ger
08-09-2010, 02:20 PM
I've already replaced the master. Is it possible to have a new one that is defective?

BADAZZ85
09-25-2010, 05:45 PM
Dumb question.... but i've seen customers replace brake parts... i.e. calipers and brought to our shop for your same exact reason and seen that the calipers were on the wrong side and bleeders were at the bottom side of caliper. just an idea

ran94ger
09-25-2010, 06:26 PM
lol, I know what you r saying, but no the bleeders r on the top.

BADAZZ85
09-25-2010, 06:59 PM
Does it stil have r.a.b.s. module valve under drivers seat frame rail? if so, i seen them "stick" after power bleeding. only available at j yards or maybe ebay. i've tapped with a hammer before and gotten them unstuck. just an idea

ran94ger
10-18-2010, 05:39 PM
yea its still the stock one. i guess i should check that.

Explorer
10-19-2010, 05:25 AM
Haven't seen this mentioned. What vacuum are you you reading? PB booster will require minimum 12hg to work properly. Not familiar with your cam, some produce low vacuum. A vacuum canister can be added for reserve if thats the problem. I'm a little concerned on my present build, but won't know till I fire it up.

allnpt0
10-20-2010, 06:44 AM
I would say that your booster is not the problem. If it fails, the pedal would be hard. The job of the booster is to reduce pedal effort when running. Since the pedal is soft when running, I would rule out the booster.

See if you can find someone with a reverse bleeder. I've had to do this on postal trucks.

Ranger Blake87
10-19-2014, 11:19 PM
You said you put on new calipers? No offense because I have done it too but are your bleeder screws above your lines? As in if they where mounted on the wrong sides they would be below the lines and bleed out nice but as soon as you start the truck you are reminded that you still have air in the line. Hope this helps because your problem sounds just like one I had. ....

Lil_red'01 edge 4.0 4x4
11-04-2014, 09:46 AM
My brakes in my 4.0 always felt week like it needs a replacement but they don't squeak and my family that has driven it says it's fine the way it is. So now I'm curious as to what you have to do to fix the problem

scottyfender
01-14-2015, 08:02 PM
My brakes in my 4.0 always felt week like it needs a replacement but they don't squeak and my family that has driven it says it's fine the way it is. So now I'm curious as to what you have to do to fix the problem

I'm having this issue with my 1988 302 with an F303 cam. I haven't found the problem yet.
Lil Red...Lafayette here also.

stateranger
01-14-2015, 09:20 PM
What type of issues?

scottyfender
01-14-2015, 09:39 PM
What type of issues?
The brake pedal is tight when I bleed them with the motor off. Once I start the motor the pedal gets real soft and goes almost all the way to the floor.

stateranger
01-14-2015, 09:54 PM
Does the pedal get softer when you open a bleeder and is someone helping you?

scottyfender
01-14-2015, 10:04 PM
Sounds like a lot air in the system. Remember pump it until the pedal gets harder then slowly open the bleeder.
I've bleed it so much that I had to fill up the reservoir twice. A buddy that owns a mechanic shop is helping me with it so we can rule out the simple things. Everything is new except the hard lines and those were blown out with air before I put calipers and cylinders on. We had the issue towards the end of the night so we haven't really messed with it much since.

stateranger
01-15-2015, 12:01 AM
Does the pedal get softer when you open a bleeder and is someone helping you?

Edited^^^ the information I gave was totally wrong.

does the pedal get softer when you open the bleeder.

scottyfender
01-15-2015, 06:24 AM
Edited^^^ the information I gave was totally wrong. does the pedal get softer when you open the bleeder.
Yes and slowly goes to the floor.

lawnmowernick
08-16-2015, 05:58 PM
I know this is kinda a older thread but did anyone ever find a fix for the problem or are you still having trouble?

scottyfender
08-16-2015, 07:01 PM
Still have my issues. I learned to live with it. I'd love to fix it but I haven't found the way to do it. I have 12 to
14 inch pounds of vacuum going to the booster.

lawnmowernick
08-17-2015, 05:56 AM
I just did the swap about a month ago and have been just worried that I was missing something I guess it's one of the down sides to a 5.0 swap

terryduanemiller
08-17-2015, 05:11 PM
I just did the swap about a month ago and have been just worried that I was missing something I guess it's one of the down sides to a 5.0 swap did you do rear disc swap? Have you modified the OEM proportioning valve? Performance cam shaft? What is idle rpm?

scottyfender
08-17-2015, 06:31 PM
I have rear drums. It's a 1988 and doesn't have the proportioning valve. Ford racing f303 cam. 800 ram idle.

terryduanemiller
08-19-2015, 09:48 AM
I have rear drums. It's a 1988 and doesn't have the proportioning valve. Ford racing f303 cam. 800 ram idle. ok, idle is to low. Performance cam can't idle at stock perimeters due to valve overlap, Raise the idle to 1000-1100 as a base. My 331 idles at 1400 my '72 roadrunner 340X idles at 1600

scottyfender
08-19-2015, 10:03 AM
It's set at 1000 now. Is
this supposed to fix the soft brake pedal issue?

Vogenitz69
08-19-2015, 10:27 AM
I just did the swap about a month ago and have been just worried that I was missing something I guess it's one of the down sides to a 5.0 swap have you tried swapping the master to the explorer master?

lawnmowernick
08-19-2015, 01:37 PM
I have a e303 and yes I did swap to the explorer rear and about the master cylinder I just put a new one on Saturday and it seemed to make the pedal feel better to a extent but not like it was

----------

Also had to numb my idle up to about 1000

Vogenitz69
08-19-2015, 01:48 PM
I have a e303 and yes I did swap to the explorer rear and about the master cylinder I just put a new one on Saturday and it seemed to make the pedal feel better to a extent but not like it was ---------- Also had to numb my idle up to about 1000 ohh I forgot about the cam. I'm throwing a cam in mine but the idle is fairly close to stock, however the engine vacuum is increased so I imagine my brakes will stay stiff or be stiffer. Hopefully lol

terryduanemiller
08-20-2015, 06:53 AM
It's set at 1000 now. Is this supposed to fix the soft brake pedal issue? booster works off vacuum created by the engine, performance cams have valve overlap creating a decrease in vacuum that is created by constant air drawn in by engines rotating assembly. Has anyone modified the proportioning valve after rear disc swap?

lawnmowernick
08-20-2015, 08:32 AM
I have never modified the proportion valve

scottyfender
08-20-2015, 03:19 PM
I have stock rear drums. 1988 had no proportioning valve.

terryduanemiller
08-21-2015, 06:07 AM
We have ran into these kind of problems building classic, restomods, pro touring cars. You may need to go to a larger diameter booster. We normally use hydrboost setups on our builds. Lincolns and some mustangs use them. Utilizes power steering pump.

137449

I do not know if they are swappable.

scottyfender
08-21-2015, 10:22 AM
Larger diameter booster? Or do you mean master cylinder?

terryduanemiller
08-21-2015, 06:49 PM
Larger diameter booster? Or do you mean master cylinder? booster