RTV SEALER/GASKET ELIMINATOR DESCRIPTION

There are two types of sealers used currently to seal GM engines. The first is R.T.V. (Room Temperature Vulcanizing) silicone which is used where a non-rigid part is assembled to a cast or rigid part such as rocker covers, oil pans, etc. The second is gasket eliminator, an anaerobic material (cures in the absence of air) which is used where two rigid parts are assembled together, such as timing case cove to cylinder block. When two rigid parts are disassembled and no gasket or sealer is readily noticeable it is sealed with gasket eliminator.

When assembling parts, use the correct material. Don't use R.T.V. on two rigid parts and don't use gasket eliminator on stamped parts such as rocker covers. Don't use R.T.V. when extreme temperatures are expected, e.g. exhaust manifold, head gasket.

Part A below provides directions for use of R.T.V. while Part B provides directions for use of gasket eliminator.

A. Directions for use of R.T.V.:

1. Surface must be clean and dry. Remove all traces of oil and old gasket material. Clean with "chlorinated" solvent, e.g. lacquer thinner, naptha. Don't use petroleum cleaners such as mineral spirits. They leave a film to which R.T.V. won't stick.

2. Cut the tube extension to approximately 1/8".

3. Apply R.T.V. to one of the clean surfaces. Totally circle all bolt holes.

4. Assemble while R.T.V. is still wet (within 3 minutes). Don't wait for R.T.V. to skin over

5. Torque bolts to specs. Don't over torque.

6. R.T.V. will cure in 15 minutes which is sufficient to allow for testing and operation of vehicle. No need to wait for R.T.V. to cure completely.

B. Directions for use of gasket eliminator:

1. Clean surfaces with a chlorinated solvent to remove all oil, grease and old material.

2. Apply a continuous bead of gdsket elimindtor to one flange. (Use of an accelerator cleaner such as 3M 008958 or equivalent is recommended prior to application of gasket eliminator. The accelerator cleaner increases the gap filling capability of gasket eliminator and speeds curing time.)

3. Spread bead evenly with your finger to get a unifom coating on the complete flange.

4. Assemble parts in the normal manner and torque to specs.

5. Vehicle can be operated after completion of assembly. No need to wait for gasket eliminator to cure.

The keys to satisfaction in using R.T.V. and gasket eliminator are following directions and using where specified. Don't cut the procedure short or leak will result.

R.T.V.'s differ in perfomance. To assure good performance, use only GM Silicone Sedler (R.T.V.) or equivalent. Known equivalent material is 3M-T3 (08660), Fel-Pro Numbers 227 and 228, Pematex Numbers 27 B.R.L.V., and G.E. Catalog Numbers 56002, 1186 and 454.

General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.