Braking Power Options

[lsintampa]

Just went out for a drive.

Pedal is soft.

On smooth pavement, if I brake hard, I'm just getting a small and very short squeal from the front - nothing from the back.

On rough pavement, braking hard, I basically get no squealing at all.

So locking them up - so to speak - is nearly impossible.

When I say the pedal is soft, there is good pressure, but not what I'd call hard.

Pumping them does nothing - pressure still feels the same.

I'm a big guy - 200 - 230 pounds. I would think that if I got on the brakes really hard that I should be able to lock all four up. Nada.

That said, the pedal travel isn't all that far either. I bled the brakes a few months ago and the pedal was easily going all the way to the floor until I got them "decent". The motor was out getting rebuilt, so there was no way to test them.

When the shop finished the motor and put it in, they "re-bled" the brakes again. I'd assume they did it right - given they do mostly BMW and Porsche work.

[mepstein]

Just went out for a drive.

Pedal is soft.

On smooth pavement, if I brake hard, I'm just getting a small and very short squeal from the front - nothing from the back.

On rough pavement, braking hard, I basically get no squealing at all.

So locking them up - so to speak - is nearly impossible.

When I say the pedal is soft, there is good pressure, but not what I'd call hard.

Pumping them does nothing - pressure still feels the same.

I'm a big guy - 200 - 230 pounds. I would think that if I got on the brakes really hard that I should be able to lock all four up. Nada.

That said, the pedal travel isn't all that far either. I bled the brakes a few months ago and the pedal was easily going all the way to the floor until I got them "decent". The motor was out getting rebuilt, so there was no way to test them.

When the shop finished the motor and put it in, they "re-bled" the brakes again. I'd assume they did it right - given they do mostly BMW and Porsche work.

You have more to do. Don't give up.

[ChrisFoley]

...
Pedal is soft.
...
When I say the pedal is soft, there is good pressure, but not what I'd call hard.
...
That said, the pedal travel isn't all that far either.

The pedal should be firm with stock calipers and a 19mm MC.
You're big enough that locking the brakes shouldn't seem all that difficult.
Instead of trying to gradually increase the force, stand on the pedal as if in a panic situation. The fronts should lock up.

Used pads don't need to be bedded.
If the calipers all work properly and you have the rear venting clearance set correctly and you can't bottom out the pedal under heavy braking, the problem is your used brake pads.

There's a big difference in coefficient of friction between various pad brands and compounds. Porterfield or KFP street pads are among the best.

[saigon71]

As others have suggested, make sure you have the system bled properly first.

What condition are your calipers in?

I had a similar situation when I got my brakes sorted out. USED rotors within spec, used brake pads in good shape, fresh system bleed & 17MM master. I was underwhelmed with the braking.

A front caliper started leaking on me so I rebuilt the fronts with a kit from PMB and installed Porterfield pads on the front, leaving the rears alone. What a difference!

[bandjoey]

Floor board flex? There are several threads on master cylinder braces. Search or someone will chime in with details.

[worn]

sorry guys,

I didn't realize how many of you posted a response. I thought I had set email notice on, but haven't gotten any notices.

Recap - to answer most of your questions.

Pads are NOT new, rotors are. The pads were (IMO) in decent shape.

I have NOT bedded anything - yet.

By not what I expected, I haven't really tried to "lock them up", but the feeling I have is that isn't going to be easy to do.

I'm on my way out to pick up some lunch. I'll do some testing and get back in a while. Don't worry, I'll do it safely.

Thanks,

Len

Glad to know you are driving it. I went from a 911 to a 914. 911s are like God's gift to stopping. The 914 feels like you have to push like hell to keep from rear ending everything in sight. They are just different.

I found two things.
1) I really can lock up the wheels when I try and cause I have good tires that stops real quick. But you have to want it. And it helps to be ready.
2) Break pads from Eric. I got the Porterfield pads and while they squeak a lot, they also have a better grip, so you don't need to push a lot.

Hope lunch was grand.

[wndsnd]

This thread got me thinking that my brakes could be better and I had not bed them. So I went out last night and followed Eric's procedure.

Noticeable improvement. Brakes will lock up without much effort and I have the 17mm MC

John.

[URY914]

Isintampa,

What part of T do you live?

[lsintampa]

I'm in North Tampa .... Carrollwood actually.

Isintampa,

What part of T do you live?

[McMark]

Glad to know you are driving it. I went from a 911 to a 914. 911s are like God's gift to stopping. The 914 feels like you have to push like hell to keep from rear ending everything in sight. They are just different.

Then your 914 is not bled out properly. (IMG:style_emoticons/default/tongue.gif)

[ThePaintedMan]

Then your 914 is not bled out properly. (IMG:style_emoticons/default/tongue.gif)

(IMG:style_emoticons/default/agree.gif) (IMG:style_emoticons/default/confused24.gif)

[worn]

Glad to know you are driving it. I went from a 911 to a 914. 911s are like God's gift to stopping. The 914 feels like you have to push like hell to keep from rear ending everything in sight. They are just different.

Then your 914 is not bled out properly. (IMG:style_emoticons/default/tongue.gif)

Thanks a lot Mark.
They isn't spongy, the pedal just doesn't feel like a power brake does. And how often do we drive cars without boosters? Takes getting used to was my point. Also I am wimpy. Where is the emoticon for old and in the way?

[stugray]

For those that say they cannot lock the brakes, there is something wrong.

The very first time I got my car back on the road after 10 years of sitting, they very first thing I did was a brake check (safety first).
One quick stab at the pedal and I locked all four up.

This was after all four calipers were rebuilt, new flex lines installed and new porterfield pads from Eric.

This was before bedding in the brakes OR final bleeding.
Bleeding after that resulted in some air in the system and a stiffer pedal.

So even a system with some air in it should still lock the brakes with minimal exertion.

[r_towle]

Glad to know you are driving it. I went from a 911 to a 914. 911s are like God's gift to stopping. The 914 feels like you have to push like hell to keep from rear ending everything in sight. They are just different.

Then your 914 is not bled out properly. (IMG:style_emoticons/default/tongue.gif)

(IMG:style_emoticons/default/agree.gif)

I have both and the 914 stops a lot faster and a lot more stable than the 911.
Mid engine versus rear engine makes stopping more immediate and controllable.

I always bleed the system, then go beat on the brakes really hard, then come back and bleed one more time....always does the trick to get any remaining air out the back brakes via the balance valve.

[Eric_Shea]

Bed the pads and bed them again.

Even old pads will benefit from being bedded in.

The real benefit from bedding is breaking in the seals on new calipers.

New seals aggressively pull the pistons back giving you a soft pedal. The more you bed the pads, the higher the pedal gets.

[lsintampa]

Bed the pads and bed them again.

Even old pads will benefit from being bedded in.

The real benefit from bedding is breaking in the seals on new calipers.

New seals aggressively pull the pistons back giving you a soft pedal. The more you bed the pads, the higher the pedal gets.

I hear ya.... I've been trying to do that and will continue. As of yet there hasn't been much difference.

There are all new o-rings etc. in the calipers, new piston seals, etc. New rotors, just old - but good pads.

That said, I'll re-bleed the system - maybe this weekend, and see where things go.

[Eric_Shea]

Also, remember, it's a 40 year old car. A lot if times we step out the latest power assisted this or that and, the 914 feels strange. When I lay on mine they "chirp" nicely and are easy to modulate so they won't lock. Sounds like you're actually close.

[brant]

and you still need to upgrade your pads....

were they textar?

do you know what they might be? there are some really cruddy cheap pads out there.

[worn]

Also, remember, it's a 40 year old car. A lot if times we step out the latest power assisted this or that and, the 914 feels strange. When I lay on mine they "chirp" nicely and are easy to modulate so they won't lock. Sounds like you're actually close.

(IMG:style_emoticons/default/agree.gif) And my 911 and TR6 both have boosters, so the transition is less pronounced. As a drivers car I an having trouble beating the teener though. Drove it to work today smiling. Hey - where did the snow go?

[larss]

I had about the same problem with my 914/4, could not lock tires at all. After changing pads to another brand I can lock the fronts quite easily and stopping ability is greately improved. Guess the new pads are softer.
Also your 19mm MC should require more pedal pressure then stock 17mm but the feel should be firmer.

Lars S