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Discussion Starter · #1 ·
My 53 plate C-Max Zetec has suffered brake failureon two occassions.

Both times the car was being driven from cold about3/4 mile. The brake pedal was applied but went hard / 'frozen' offering very little brake performance.

I have searched the net and it seems this may be an issue with the servo vacuum hoseor the valve which sticks until the car has warmed up. Does this sound feasible?

Where can I find this hose or valve to inspect? Or a diagram of where it is (my ford-xpert link does not work any more)?

My local Ford garage has offered to take a look but this always ends up being expensive.

thanks in advance
 

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It sounds like it could be the servo, it depends wether you have a petrol or diesel, not sure what the set up is on newer cars, but on older cars a petrol engine would supply the pressure to the servo from the top of the engine via a plastic pipe, just find the servo and you will see a plastic pipe coming from it, if it's a diesel the vacume is usually supplied from the alternator, so the part on the alternator that supplies the vacume could be playing up.
 

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Discussion Starter · #3 ·
Thanks. This is a 2.0TDCI.

I've just had it up in the air to poke around underneath and can not see anything particularly worrying. Without a Haynes manual (not available for the C-MAX) I don't really feel I can start stripping things down to inspect them.



I guess I am now at the mercy of the dealer whohave no time until Tuesday.
 

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Hopefully this lot may help


Symptom Chart<?: prefix = o ns = "urn:schemas-microsoft-com:eek:ffice:eek:ffice" />
Condition(s):

o Brakes pull or drift
o The red brake warning indicator is always on
o Vibration when the brakes are applied
o Pedal goes down fast
o Pedal eases down slowly
Possible Source(s):
Air in the system.
Action(s) to take:
BLEED the brake system.

Possible Source(s):
Malfunctioning brake master cylinder.
Low engine vacuum (stationary).
Action(s) to take:
Go to «Pinpoint Test B»

Pedal is low or feels spongy
Possible Source(s):
Worn brake shoes or brake pads.
Action(s) to take:
INSTALL new brake shoes or brake pads. For additional information, refer to «Section 206-02».For additional information, refer to «Section 206-03».For additional information, refer to «Section 206-04».

Possible Source(s):
Air in the system.
Action(s) to take:
CHECK for leaks. BLEED the brake system.

Brake lockup during light brake pedal force

Excessive or erratic pedal travel
Possible Source(s):
Worn brake shoes or brake pads.
Action(s) to take:
INSTALL new brake shoes or brake pads. For additional information, refer to «Section 206-02».For additional information, refer to «Section 206-03».For additional information, refer to «Section 206-04».

Possible Source(s):
Wheel bearings
Action(s) to take:
CARRY OUT a brake disc runout check. For additional information, refer to «Brake Disc Runout Check -» in this Section.

Brake drag

Excessive brake pedal effort
Possible Source(s):
Worn or contaminated brake shoes or brake pads.
Action(s) to take:
INSTALL new brake shoes or brake pads. For additional information, refer to «Section 206-02».For additional information, refer to «Section 206-03».For additional information, refer to «Section 206-04».

Possible Source(s):
Malfunctioning vacuum pump (diesel).
Action(s) to take:
INSTALL a new brake vacuum pump.

Possible Source(s):
Disconnected or damaged brake booster vacuum pipe.
Action(s) to take:
CONNECT or INSTALL a new brake booster vacuum pipe as necessary.

Possible Source(s):
Brake booster.
Action(s) to take:
Go to «Pinpoint Test D»

Brake noise

Slow or incomplete brake pedal return

B1 CHECK THE BRAKE PEDAL OPERATION
1 Depress the brake pedal.
Does the pedal ease down slowly?
Yes
Go to «B2».

No
Refer to the Brake Master Cylinder Component Test in this procedure.

B2 CHECK FOR BRAKE SYSTEM LEAKS
1 Check for external brake system leaks.
Are any leaks present?
Yes
REPAIR as necessary. ADD fluid and BLEED the brake system. TEST the system for normal operation.

No
Go to «B3».

B3 PERFORM A BRAKE MASTER CYLINDER BYPASS CONDITION TEST
1 Carry out a brake master cylinder bypass Condition Test. Refer to the Brake Master Cylinder Component Test in this procedure.
Was a concern found?
Yes
INSTALL a new brake master cylinder. For additional information, refer to «Section 206-06». TEST the system for normal operation.

No
Go to «B4».

B4 CHECK THE BRAKE BOOSTER CHECK VALVE
1 Disconnect the brake booster check valve vacuum hose at the manifold.

2 Blow into the hose attached to the brake booster check valve.
Does air pass through the valve?
Yes
INSTALL a new brake booster check valve.

No
Go to «B5».

B5 CHECK THE BRAKE BOOSTER CHECK VALVE VACUUM
1 Run the engine at idle.

2 Using a suitable vacuum gauge, check the vacuum pressure.
Is the vacuum pressure above 40.5 kPa (0.4 bar) with the brake booster non-operational?
Yes
VERIFY the customer concern.

No
INSTALL a new brake booster check valve vacuum hose. TEST the system for normal operation

D1 CHECK BRAKE APPLICATION
1 With the engine off, apply and release the brake pedal five times to deplete all vacuum from the brake booster. Apply the brake pedal, hold with light pressure. Start the engine.
Does the brake pedal hold?
Yes
Go to «D2».

No
Go to «D3».

D2 CHECK THE BRAKE BOOSTER FOR LEAKS
1 Run the engine at approximately 1000 rpm, release the accelerator pedal and turn the engine off. Wait 90 seconds and apply the brakes. Two or more brake applications should be power assisted.
Does the brake booster work?
Yes
VERIFY the customer concern.

No
Go to «D4».

D3 CHECK THE BRAKE PEDAL LINKAGE
1 Disconnect the actuator rod from the pedal pin and fully depress the brake pedal.
Did the pedal move freely?
Yes
VERIFY the customer concern.

No
INSTALL new brake pedal bushings. TEST the system for normal operation.

D4 CHECK THE BRAKE BOOSTER CHECK VALVE
1 Disconnect the brake booster check valve vacuum hose at the manifold.

2 Blow into the hose attached to the brake booster check valve.
Does air pass through the valve?
Yes
INSTALL a new brake booster check valve. TEST the system for normal operation.

No
Go to «D5».

D5 CHECK THE BRAKE BOOSTER CHECK VALVE VACUUM
1 Run the engine at idle.

2 Using a suitable vacuum gauge, check the vacuum pressure.
Is the vacuum pressure above 40.5 kPa (0.4 bar) with the brake booster non-operational?
Yes
Go to «D6».

No
INSTALL a new vacuum hose and fittings. TEST the system for normal operation.

D6 CHECK THE BRAKE BOOSTER
1 Check the brake booster. REFER to the Brake Booster Operation Check in this procedure.
Is the brake booster OK?
Yes
VERIFY the customer concern.

No
INSTALL a new brake booster. For additional information, refer to «Section 206-07».TEST the system for normal operation.. (This is probably dealer territory)

# Diesel Brake Vacuum pump is on the end of the camshaft


Component Tests
Hydraulic Leak Check
Note:
There is a common clutch and brake fluid reservoir, therefore it is possible that a clutch leak can lead to reduction in the reservoir level.

It is possible that all evidence of fluid leakage may have washed off if the vehicle has been operated in rain or snow, as brake fluid is water-soluble. Refill the system, bleed then apply the brakes several times. Examine the system to verify that the reservoir fluid level is actually dropping. Locate and repair the external leak. If the fluid level drops and no external leak can be found, check for a brake master cylinder bore end seal leak.

Brake System Check
Brake Pedal Reserve Check
Where a low brake pedal or the feel of a bottomed-out condition exists, check for brake pedal reserve.

1.Operate the engine at idle with the transaxle in the NEUTRAL position.

2.Apply the brake pedal lightly three or four times.

3.Allow 15 seconds for the vacuum to replenish the brake booster.

Note: This increased resistance may feel like something has bottomed out.

4.Apply the brake pedal until it stops moving downward or an increased resistance to the pedal travel occurs.

5.Hold the brake pedal in the applied position and raise the engine speed to approximately 2000 rpm.

Note: The additional movement of the brake pedal is the result of the increased engine manifold vacuum which exerts more force on the brake booster during engine rundown. This means that additional stroke is available in the brake master cylinder and the brake system is not bottoming out.

6.Release the accelerator pedal and observe that the brake pedal moves downward as the engine returns to idle speed.

Brake Booster Functional Test
Inspect all hoses and connections. All unused vacuum connectors should be capped. Hoses and their connections should be correctly secured and in good condition with no holes and no collapsed areas. Inspect the check valve on the brake booster for damage.

Brake Booster Operation Check
1.Check the hydraulic brake system for leaks or low fluid.

2.With the transaxle in the NEUTRAL position, stop the engine and apply the parking brake. Apply the brake pedal several times to exhaust all the vacuum in the system.

3.With the engine turned off and the vacuum in the system exhausted, apply the brake pedal and hold it down. Start the engine. If the vacuum system is operating, the brake pedal will tend to move downward under constant foot pressure. If no motion is felt, the vacuum booster system is not functioning.

4.Remove the vacuum hose from the brake booster. Manifold vacuum should be available at the brake booster end of the hose with the engine at idle speed and the transaxle in the NEUTRAL position. Make sure that all unused vacuum outlets are correctly capped, hose connectors are correctly secured and vacuum hoses are in good condition. When it is established that manifold vacuum is available to the brake booster, connect the vacuum hose to the brake booster and repeat Step 3. If no downward movement of the brake pedal is felt, install a new brake booster. For additional information, refer to «Section 206-07».

5.Operate the the engine a minimum of 10 seconds at approximately 1200 rpm. Stop the engine and let the vehicle stand for 10 minutes. Then, apply the brake pedal with approximately 89 N (20 lb) force. The pedal feel (brake application) should be the same as that noted with the engine operating. If the brake pedal feels hard (no power assist), install a new vacuum check valve and then repeat the test. If the brake pedal still feels hard, install a new brake booster. For additional information, refer to «Section 206-07». If the brake pedal movement feels spongy, bleed the brake system.

Brake Master Cylinder
Usually, the first and strongest indicator of anything wrong with the braking system is a feeling through the brake pedal. In diagnosing the condition of the brake master cylinder, check pedal feel as evidence of a brake concern. Check for the red brake warning indicator illumination and the fluid level in the master cylinder reservoir.

Normal Conditions
The following conditions are considered normal and are not indications that the brake master cylinder is in need of service.

Modern brake systems are not designed to produce as hard a pedal effort as in the past. Complaints of light pedal efforts should be compared to pedal efforts of another vehicle, of the same model and year.

During normal operation of the brake pedal, the fluid level in the reservoir will rise during brake pedal application and fall during release. The net fluid level (i.e., after brake pedal application and release) will remain unchanged.

A trace of brake fluid will exists on the brake booster shell below the master cylinder mounting flange. This results from the normal lubricating action of the master cylinder bore end seal.

The fluid level will fall with brake shoe and lining wear.

Abnormal Conditions
Note: Prior to performing any diagnosis, make sure the brake system warning indicator is functional.

Changes in brake pedal feel or travel are indicators that something could be wrong with the braking system. The diagnostic procedure and techniques use brake pedal feel, warning indicator illumination and low brake fluid level as indicators in diagnosing braking system concerns. The following conditions are considered abnormal and indicate that the brake master cylinder is in need of service.

The brake pedal goes down fast. This could be caused by an external or internal leak.

The brake pedal eases down slowly. This could be caused by an external or internal leak.

The brake pedal is low and or feels spongy. This condition may be caused by no fluid in the brake master cylinder reservoir, reservoir cap vent holes clogged or air in the hydraulic system.

The brake pedal effort is excessive. This may be caused by a bind or obstruction in the pedal or linkage, clogged fluid control valve or insufficient booster vacuum.

The rear brakes lock up during light pedal force. This may be caused by incorrect tire pressures, grease or fluid on the brake shoes and linings, damaged brake shoes and linings, incorrectly adjusted parking brake, or damaged or contaminated brake pressure control valves.

The brake pedal effort is erratic. This condition could be caused by a brake booster malfunction, extreme caliper piston knock back or incorrectly installed brake shoes and linings.

The red brake warning indicator is ON. This may be caused by low fluid level, ignition wire routing too close to the fluid level indicator assembly, or float assembly damage.

Bypass Condition Test
1.Check the fluid in the brake master cylinder reservoir. Fill the brake master cylinder reservoir if low or empty.

2.Observe the fluid level in the brake master cylinder reservoir. If after several brake applications, the fluid level remains the same, measure the wheel turning torque required to rotate the wheels with the brakes applied as follows:

Place the transaxle in the NEUTRAL position. Raise and support the vehicle. For additional information, refer to «Section 100-02».

Apply the brakes with a minimum of 445 N (100 lb) and hold for approximately 15 seconds. With the brakes still applied, exert a torque on the front wheels of 10.1 Nm (75 lb ft). If either wheel rotates, install a new brake master cylinder. For additional information, refer to «Section 206-06».

Non-Pressure Leaks
Any empty brake master cylinder reservoir condition may be caused by two types of non-pressure external leaks.

Type 1: An external leak may occur at the brake master cylinder reservoir cap because of incorrect positioning of the gasket and cap. Reposition the cap and gasket.

Type 2: An external leak may occur at the brake master cylinder reservoir mounting seals. Service such a leak by installing new seals.
 

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Discussion Starter · #5 ·
Thanks,

I guess this is extracted from the TIS (my kids scratched the CD of my ebay version up).

I eventually established where the vacuum pump was (end of camshaft) and it seems to suck okay and there were no leaks when blowing back up the pipe.This was limit of my checks as all other parts seem to be buried behind the bulkhead / dash and I do not have pressure gauge. So it therefore inconclusive.

Any ideas how much a new pump would be and whether it is simple to fit? I could attempt this myself as a first step.
 

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Hi Folks,
I realise thats it's been over a year since this thread was posted in, but I am very interested in the fault described. I too have a similar, if not identical, problem with a 54 plate cmax diesel. I wonder if it would be possible if saint.vince, or indeed anyone else, could advise me on the part number for this replacment vacuum pump valve, so that I may obtain and fit one to my car.

Many thanks to all who may take the time to read this, and hopefully reply :)
 

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Discussion Starter · #8 ·
I took it to ford who did the work free of charge although I had central locking fault at same time which cost small fortune.

You may find the following useful to argue why this should be done free of charge. I did not follow up with VOSA but probably should have done as this probably affects earlier vehicles than ford claim.

http://www.vosa.gov.uk/vosa/apps/recalls/searches/expand.asp?uniqueID=02977976E10BBB308025735500353020&freeText=Blank&tx=BL

http://www.vosa.gov.uk/vosa/apps/recalls/searches/expand.asp?uniqueID=24E73DECF50DE9C6802575AF002C8B13&freeText=Blank&tx=BL

good luck
 

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I also rang my local Ford dealer and I TOLD them that there was a VOSA recall for the vacuum valve to be replaced , as it is dangerous .I have a cmax 2.0ghia on an 04 plate , and they fixed it FOC , so my advice just ring your local dealer tell them you've been on the VOSA website and there is a recall and you'd like it done asap , my dealer did'nt mentionthe fault was not on my model , they just did it. Thankyou Evans Halshaw Chester
 

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It would seem that VOSA website only refers to vehicles buit from 205 only. Is my inturpretation correct? Also does this apply to all types of C-Max.
 

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I think it must apply to all models as the dealer did'nt even mention that my car was on an 04 , and the VOSA websiites says 2005 , I just chanced my arm and they did it hassle free.
 
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