Brake pedal mushy - FIXED

[MrChris]

I would clamp the rear calipers 1st just to make sure the problem is with the front.
Sticking rear sliders or overly adjusted hand brake cables would also give the same effect.

Good shout thanks! Any idea how to clamp off braided brake lines though? Wouldn't that damage them?

Not only was I on that thread I have test driven that owners car.
https://www.spyderchat.com/threads/driving-impressions.138401/page-2

What is not in the posts is my conversation with the driver that told me that he bought the same refurbish brand as my Honda which has the same issues but worse.
If your ABS module is activating then it should be ok. The problem is the weird travel feel in the pedal which I thought was fade from new pads and rotors but I was being too optimistic.

Later on I determined that it must be the refurbished calipers so I gave him for testing my used front calipers that I replaced for my Willwood to test to see if it improved the braking feel. I never heard back from him again.

Hmm, sounds like it might be worth cancelling my order of the Pagid calipers and just sourcing some known good calipers or splashing out on new from Toyota (I assume they would be new?).

[MrChris]

My Padgid calipers were perfect. New Toyota will be insanely expensive!

I totally support the diagnose your issue first approach by isolating calipers etc.

But yes, you cannot use hose clamps on braided hoses.

Make a stopper with some brake pipe and flairs, that would be my approach.

If your calipers are leaking air, I would expect to see fluid leaking too.

I think you are making this more complicated than it needs to be, its a very primitive hydraulic system. Just isolate bits and see if it works.

Even unbolt the calipers then put G clamps round them, see if the pedal is hard or not etc.

Agree with you that it is more complicated than it needs to be... I just wish I had more time to work on my 2. Doesn't help that it lives outside and not in a garage. Dark nights and rain don't help.

Great idea on using clamps on the calipers, didn't even cross my mind. I'll isolate calipers using this approach next.

Phoned Toyota earlier and calipers are approx. £250 each on the front.

[Dev]

Good shout thanks! Any idea how to clamp off braided brake lines though? Wouldn't that damage them?

Hmm, sounds like it might be worth cancelling my order of the Pagid calipers and just sourcing some known good calipers or splashing out on new from Toyota (I assume they would be new?).

I suppose it depends on where you are and what works. Maybe a different refurb I don't know but it will never be as good as a factory fresh part were material is removed to refurbish it even if tolerances are acceptable .
  Based on my bad experience and the experience of others the clear choice for me if I was in a similar situation again is salvage from a known vehicle with low miles with a 15 to 30 day warranty. I can find them online from reputable salvage yards or even eBay.  I did this for a caliper on another car that had 30k miles before it was totaled and the part looked fairly new including the rubber seal. Cleaned it with some brake cleaner and it worked like it should until I sold the car.
I have had greater success with reputable salvage low milage parts because it is the closest thing to OEM without the high cost.
Every time I try a third party part its like rolling the dice but I still do from time to time so it depends.   

[Dev]

Here is a nice read I found today. Similar story different day from a different supplier than the ones from the other post. A lot of these remans are garbage.

https://www.spyderchat.com/threads/braking-issues-at-my-wits-end-need-advice.160745/#post-2197465

The problem here is he decided to remedy the situation by buying another set of remans from MWR which sells under their QRP brand which is not very good.
New does not mean remans but I am sure there might be some good ones done right but who really knows what goes into the process to machine them correctly. The attractive low price is not always what it seems. 

[MrChris]

Thanks @Dev appreciate the comments.

By way of an update I tried @mr2garageswindon suggestion of clamping off the front calipers this morning and found one of my carrier bolts rounded out and a slider starting to stick. So I've called up @J-SPEC and I've got 2 calipers with carriers on order. Then will do another full bleed and I hope I'm there..!

[MikeBoo]

Hopefully you're getting close to sorting this.
You mentioned in your original post:

I've had 2 new rear calipers, fronts have been refurbished with new pistons and seals

I took this as that you had just recently replaced the rear and refurbished the front calipers and since then the brake pedal was mushy, is my assumption correct?
If it is then logic dictates the issue is related to these parts rather than anything else.

[Joesson]

Hopefully you're getting close to sorting this.
You mentioned in your original post:I took this as that you had just recently replaced the rear and refurbished the front calipers and since then the brake pedal was mushy, is my assumption correct?
If it is then logic dictates the issue is related to these parts rather than anything else.

Having replaced the rear and renovated the front calipers on my car, abrading the discs and  replacing the part worn pads, in the same relative positions, the pedal did feel different but not a hydraulic mushiness.

[MrChris]

Hopefully you're getting close to sorting this.
You mentioned in your original post:I took this as that you had just recently replaced the rear and refurbished the front calipers and since then the brake pedal was mushy, is my assumption correct?
If it is then logic dictates the issue is related to these parts rather than anything else.

Yep, I replaced the rears with Ridex calipers from Autodoc (and btw through all of this the handbrake is still effective, so I guess that means they're good?!), then I refurbed the fronts myself with new seals and pistons. So yes, logically the parts I refurbished are most likely the weak link. The fact I found the carrier slider to be sub-optimal is likely contributing to the issue, plus I believe air might be getting in somewhere around the caliper too...

Andy at @J-SPEC confirmed that it's extremely unlikely to be the master cylinder unless it ran dry (it hasn't).

Having replaced the rear and renovated the front calipers on my car, abrading the discs and  replacing the part worn pads, in the same relative positions, the pedal did feel different but not a hydraulic mushiness.

Different how?

[Joesson]

@MrChris
Like the used pads were bedding in again onto the used discs. I guess they would  be in marginally different positions, one to another and so the minute highs and lows were like two corrugated surfaces coming together.
Some, for me, severe use of the pedal was necessary to begin to eliminate that feel.

[potge]

Having read all the proposals going to more unlikely issues.

Are your bearings okay? If they are not, or something in the assembly is not as it should it could be pad knockback. However, if you experience repeatedly even on straight line most probably is not the culprit. You can also measure the runout on cleaned hub and then on the disc to get a bit more insight.

[MrChris]

While I wait for JSPEC calipers and carriers to arrive I found this video I took the other day. If anyone watches it then this is description of what I'm experiencing (all done stationary on my drive):

1. Engine off, foot on brake pedal.
2. Engine starts, pedal depresses and stops.
3. Pump twice and pedal is at expected position (and holds).
4. Couple more pumps then off the brake pedal for extended time.
5. Depress pedal and it goes down quite a bit, followed by a pump and then a second pump: brake is now at acceptable position and feeling good.
6. Repeat step 5 and same results.
7. Hold brake and turn engine off, brake holds as expected.
8. Pump brake while engine off, has some movement but is reasonably solid.

@potge I believe my bearings are fine.

[MrChris]

Well it's fixed.

Andy @J-SPEC sorted me out with 2 calipers with carriers. Just fitted them, bled the hell out of them. Got in the car, pumped the brakes up, went for a drive and what do you know... all good.

So it could have been my caliper rebuild but I actually think it was the carrier sliders being at fault. The one's from Andy were so much smoother. I could have sworn that they carriers seemed fine when I originally did the fronts but I guess when you haven't got anything to compare to...

Anyway, I'll put a TL:DR on my first post.

Saga over. Have a piccie... and no I haven't painted them, they turned up like that - now I have green on the front and red on the back 

[shnazzle]

Keep it green as  memento of good times

[Trebordoody]

Well done on your perseverance!

Having fought my sticky brakes, trying (and failing) to do a brake bleed with an Eezibleed spare tyre pressure system, and eventually doing a caliper rebuild for one of the fronts that had a seized piston, I understand how frustrating and scary it can be. As a real newbie to mechanics, I find dealing with critical components like brakes is a bit overwhelming at first, but the forum really helps get you through it with a bit of confidence.

Keeping it green is a very cool idea from @shnazzle 

[MrChris]

@Trebordoody absolutely, and the help and encouragement from this club is fantastic as this thread shows. It also goes to show that sometimes you just need to replace more stuff than you first anticipated!

[MrChris]

Keep it green as  memento of good times

Also green for: let's goooo